Re: [algogeeks] Re: Sort 7 numbers of 4 digits each

2012-08-07 Thread SHOBHIT GUPTA
check dis link http://www.1771.in/how-many-comparisons-are-needed-in-worst-case-if-we-have-to-sort-7-numbers-each-of-4-digit.html On Tue, Aug 7, 2012 at 9:38 PM, Sambhavna Singh wrote: > Its radix sort.. > > > On Fri, Aug 3, 2012 at 4:39 PM, Navin Gupta wrote: > >> I think the no. of comparison

Re: [algogeeks] Re: Sort 7 numbers of 4 digits each

2012-08-07 Thread Sambhavna Singh
Its radix sort.. On Fri, Aug 3, 2012 at 4:39 PM, Navin Gupta wrote: > I think the no. of comparisons depend upon the type of sorting used. > Please specify the sorting algorithm used:- > 1:- in case of bubble sort it is - 21 > 2:- in case of radix sort it is - 84 > > > > On Tuesday, 31 July 201

[algogeeks] Re: Sort 7 numbers of 4 digits each

2012-08-03 Thread Navin Gupta
I think the no. of comparisons depend upon the type of sorting used. Please specify the sorting algorithm used:- 1:- in case of bubble sort it is - 21 2:- in case of radix sort it is - 84 On Tuesday, 31 July 2012 21:21:30 UTC+5:30, Sambhavna Singh wrote: > > Hi, > > We need to sort 7 numbers e

[algogeeks] Re: Sort

2012-06-22 Thread joker
On Tuesday, 13 July 2010 17:32:43 UTC-7, Gene wrote: > > On Jul 13, 2:46 pm, Devendra Pratap Singh > wrote: > > @gene > > > > thanx for the working code > > > > but can u explain its working more clearly > > > > On Jul 13, 11:21 pm, Gene wrote: > > > > > > > > > On Jul 10, 5:18 pm,

Re: [algogeeks] Re: sort 2D array

2012-01-27 Thread Sourabh Singh
@all I have come across this question earlier. it's a young's tableaus ( cormen pg. 167 ) can be treated as min heap. solution can be found in mit online study material. i'll post the link here as soon as i remember it. On 1/24/12, atul anand wrote: > @praveen : k way merge would require extra

Re: [algogeeks] Re: sort 2D array

2012-01-24 Thread atul anand
@praveen : k way merge would require extra space right??question is to do it in place. On Tue, Jan 24, 2012 at 5:47 PM, praveen raj wrote: > This can be done... k way merge... > > c- number of columns > r- number of rows > > In O(c*r*log(r)) > > PRAVEEN RAJ > DELHI COLLEGE OF ENGINEERING > >

Re: [algogeeks] Re: sort 2D array

2012-01-24 Thread praveen raj
This can be done... k way merge... c- number of columns r- number of rows In O(c*r*log(r)) PRAVEEN RAJ DELHI COLLEGE OF ENGINEERING -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups

Re: [algogeeks] Re: sort 2D array

2012-01-22 Thread Arun Vishwanathan
@ lucifer: thank you ! On Sun, Jan 22, 2012 at 4:12 PM, Lucifer wrote: > @Arun, > > Nope.. the loop exits only when there are no more swaps possible... > > Let me explain with an example.. > x b c > d e f > g h i > > say x > min(b,d) , where min(b,d) = b, > > Hence, swap happens.. > > b

[algogeeks] Re: sort 2D array

2012-01-22 Thread Lucifer
@Arun, Nope.. the loop exits only when there are no more swaps possible... Let me explain with an example.. x b c d e f g h i say x > min(b,d) , where min(b,d) = b, Hence, swap happens.. b x c d e f g h i say, x > min(c, e), where min(c,e) = e.. Hence, swap takes place.. b

Re: [algogeeks] Re: sort 2D array

2012-01-22 Thread Arun Vishwanathan
@lucifer: yes I get that...I was just saying that after a swap has happened within the while loop ( since x > min(b,d) might have been the case ) , then in the next looping within while, break wud happen right? meaning it doesnt stay in the while after a swap happens... On Sun, Jan 22, 2012 at 3:

[algogeeks] Re: sort 2D array

2012-01-22 Thread Lucifer
@Arun If you read the post in which i have explained the process properly, the following is also present: while(1) { If x <= min (b,d ), /* here b is nothing but the element placed next to 'x' on the same row.. d is the element placed right below 'x' in the same column... then we are done...*/

Re: [algogeeks] Re: sort 2D array

2012-01-22 Thread Arun Vishwanathan
@lucifer:nice explanation !... just to make a small clarification, in your stabilisation part u jus compare x with min (b,d) , make a swap if necessary and then next time u compare it shud be <=min(b,d) and so u break. x b c d e f g h i so now after breaking x is less than both b a

[algogeeks] Re: sort 2D array

2012-01-14 Thread Gaurav Kalra
Bases on algorithm suggested by Lucifer, I have coded the problem in C (please see attachment). The code has been tested against the following test cases: 1 3 4 8 9 2 5 18 25 50 6 7 22 45 55 and 1 2 7 3 5 8 4 6 9 -- You received this message because you are subscribed to the Google Groups "

[algogeeks] Re: sort 2D array

2012-01-13 Thread gvk
Awesome Explanation Lucifer!! On Wednesday, January 11, 2012 10:25:01 PM UTC+5:30, Lucifer wrote: > > @Ankur.. > > I will try to explain the approach with an example.. > -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To view this discussi

[algogeeks] Re: sort 2D array

2012-01-13 Thread gvk
Awesome!! -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To view this discussion on the web visit https://groups.google.com/d/msg/algogeeks/-/RsqwEYjbA3kJ. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from

Re: [algogeeks] Re: sort 2D array

2012-01-12 Thread pankajsingh
@prakash...ya i realized that and it will be sorted row and column wise.which will become same as forming min-heapand my algo will become same what lucifer had already specified... -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To po

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread prakash y
@pankajsingh, did u observe the array in the 4th step? I think it will be like this 1 2 3 4 9 5 8 18 25 50 6 7 22 45 55 The second column is not sorted. You need to sort not only the rows, but also the columns accordingly. I think it will become more complex. On Wed, Jan 11, 2012 at 5:51 PM, pa

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread pankajsingh
I thought of a simpler algo, i m using the property of this matrix That is. a[i][0] is smallest of a[i][] and a[i+1][]so on,so to decide next smallest element i will only consider a[i][0]... i will swap element if required and sort the row(too by swapping) if element are changed. on the above

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread pankajsingh
I thought of a simpler algo, i m using the property of this matrix That is. a[i][0] is smallest of a[i][] and a[i+1][]so on,so to decide next smallest element i will only consider a[i][0]... i will swap element if required and sort the row(too by swapping) if element are changed. on the above

[algogeeks] Re: sort 2D array

2012-01-11 Thread sravanreddy001
@Lucifer: great explanation. and very good idea that the matrix is like a 'heap' I didn't see your post.. not I get it.. :) -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To view this discussion on the web visit https://groups.google.com/

[algogeeks] Re: sort 2D array

2012-01-11 Thread Lucifer
@sravan and Ashish.. In the second half of the post that starts with.. /* @Ankur.. I will try to explain the approach with an example.. */ i have explained how the heap-readjustment will work.. --- Plz go thru it and let me know if further clarification is required... On Jan 11, 10

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread Ashish Goel
heapify/readjust (submatrix rooted at A[row+1][0] ) how do we do this the element moved as part of swap may fit in anywhere in submatrixrow+1,0 to m,n Best Regards Ashish Goel "Think positive and find fuel in failure" +919985813081 +919966006652 On Wed, Jan 11, 2012 at 11:14 PM, Lucifer wro

[algogeeks] Re: sort 2D array

2012-01-11 Thread sravanreddy001
@Lucifer, I was thinking in the similar lines, but, I couldn't get the exact way of re-arranging the sub-matrix, Please throw some inputs or links which can solve that "Rearrange in " O(M+N) time. Problem I see: when we identify the position for a[i+1][0], and we repace it with a[k][l], the

[algogeeks] Re: sort 2D array

2012-01-11 Thread Lucifer
@atul.. Missed ur previous post by a couple of mins.. Nyways it seems u got it .. :).. On Jan 11, 10:44 pm, Lucifer wrote: > @atul.. > > Yup, its incorrect... because as i said.. for A[i][j] its children are > at A[i+1][j] and A[i][j+1].. > Hence, if u look at the array as a 1D array, then your

[algogeeks] Re: sort 2D array

2012-01-11 Thread Lucifer
@atul.. Yup, its incorrect... because as i said.. for A[i][j] its children are at A[i+1][j] and A[i][j+1].. Hence, if u look at the array as a 1D array, then your LEFT and RIGHT indices would be incorrect... Also, For any A[i][j], if it doesn't hold the correct value then the min element is alway

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread atul anand
correction : /*set min at position A[i+1][0] after heafiying */ On Wed, Jan 11, 2012 at 11:07 PM, atul anand wrote: > @Lucifier : > yes i didnt hepified properly in my previous post intentionally. i only > purpose was to set min at position A[i+1][j] after heafiying.( rest i dint > care ) . > >

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread atul anand
@Lucifier : yes i didnt hepified properly in my previous post intentionally. i only purpose was to set min at position A[i+1][j] after heafiying.( rest i dint care ) . secondly about the complexity, what i was saying if given array is:- 1 3 4 8 9 2 5 18 25 50 6 7 22 45 55 now comparing 3 > 2 , s

[algogeeks] Re: sort 2D array

2012-01-11 Thread Lucifer
@atul.. Sorry, but i don't agree with both of ur posts... First of all, the complexity won't be log(m*n) for heapifying.. log(m*n) is valid in case of a heap represented in the form of a binary tree.. But, i have have repeatedly stressing in my previous posts that the submatrix heap is not a bin

[algogeeks] Re: sort 2D array

2012-01-11 Thread Lucifer
@Ankur.. I will try to explain the approach with an example.. Say the given matrix (sorted row wise and column wise) is as follows: a1 a2a3 a4 b1 b2b3 b4 c1 c2c3 c4 d1 d2d3 d4 Now, we want to sort the 2D array such that when all the rows are aligned se

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread atul anand
abt complexity. now considering worst case scenario where swapping take place every time. now assuming that we heapifying procedure , considering rows from i+1 to M as M-(i+1) 1-dimensional array . now heapify will take O(log(m*n)) time so complexity would be M*N*log(M*N)) please correct me if i

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread atul anand
@Lucifier : it seem that the sub-matrix need to be heapifyed for A[i][j] is A[i+1][j] to A[row][col] there is no need to include A[i][j+1] to A[i][col] for A[i][j] as you have mentioned above. for eg :- 1 3 4 8 9 // 3 > 2 , so swap and heapify 2 5 18 25 50 6 7 22

[algogeeks] Re: sort 2D array

2012-01-11 Thread Gene
Think about the cost of picking the minimum. It's not O(1). On Jan 11, 3:34 am, Sanjay Rajpal wrote: > How can it be mn log mn ? > > it will be O(mn) as we elements are sorted, we simply pick minimum at each > iteration of the loop. Since there are mn elements, so complexity will be > O(mn). > >

[algogeeks] Re: sort 2D array

2012-01-11 Thread Lucifer
@Ankur.. Yes... If you follow the algo that i have presented above and use Atul's example you will be able to figure out.. Maybe, the confusion is regarding heapfying.. ryt?? I am assuming so.. Now as i said a submatrix rooted at A[i , j] is nothing but a heap where its subtrees share a few node

[algogeeks] Re: sort 2D array

2012-01-11 Thread Lucifer
@atul.. Complexity of heapifying(basically re-stabalizing the heap) is (m - i + j) when an element A[i][j] is swapped with A[i+1][0] as an impact of A[i][j] > A[i+1][0].. On Jan 11, 4:44 pm, Dipit Grover wrote: > @Shady : you would definitely need two index variables for each array I > feel. -

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread Dipit Grover
sorry I mean 1 variable per each array -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread Dipit Grover
@Shady : you would definitely need two index variables for each array I feel. -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algo

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread Ankur Garg
@Lucifer I am not getting how u r working with heapifying each time .. Initially the array is such that minimum value is ay (0,0) and and max at index (m-1,n-1) Now when u swap a value Then u heapify i.e. make the prior arrangement again but that in turn will lead to few swaps and so on...(Recu

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread atul anand
i have little doubt in complexity of proposed algo.. aren't we including complexity of heapifying each time. ?? On Wed, Jan 11, 2012 at 2:57 PM, Lucifer wrote: > @dipit .. > > Yup you are correct.. > > Say, no of rows = M and no. of cols = N, > Time complexity = sum over all i (1 to M} { N*(M+N

[algogeeks] Re: sort 2D array

2012-01-11 Thread Lucifer
@shady.. Look out for in-place merge sort... On Jan 11, 4:23 pm, shady wrote: > any idea on how to merge two sorted arrays of size m and size n in O(m+n) > time and without extra space ? > > > > > > > > On Wed, Jan 11, 2012 at 3:22 PM, Dipit Grover wrote: > > @ all k-way people : I dont get it

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread atul anand
@shady : http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.22.5514&rep=rep1&type=pdf it is not easy to merge sorted array inplace. check this link..hope this help. On Wed, Jan 11, 2012 at 4:53 PM, shady wrote: > any idea on how to merge two sorted arrays of size m and size n in O(m+n) >

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread shady
any idea on how to merge two sorted arrays of size m and size n in O(m+n) time and without extra space ? On Wed, Jan 11, 2012 at 3:22 PM, Dipit Grover wrote: > @ all k-way people : I dont get it how the complexity would be O(m*n) . I > just went through the algo and I feel that one would need t

Re: [algogeeks] Re: sort 2D array

2012-01-11 Thread Dipit Grover
@ all k-way people : I dont get it how the complexity would be O(m*n) . I just went through the algo and I feel that one would need to find the minimum element among the head-elements of all individual row-arrays, for all the resulting m*n elements. I say so since we may not necessarily have a sort

[algogeeks] Re: sort 2D array

2012-01-11 Thread Lucifer
@All... Infact if we closely observe, then for A[row][col] when replaced with A[row+1][0].. Then on heapifying the matrix rooted at A[row+1][0], the new value will have shifts within the submatrix (A[row+1][0] , A[M] [col]) Hence, the actual time complexity would be : Say, no of rows = M and no

[algogeeks] Re: sort 2D array

2012-01-11 Thread Lucifer
@dipit .. Yup you are correct.. Say, no of rows = M and no. of cols = N, Time complexity = sum over all i (1 to M} { N*(M+N-i) } = M * N * (M + 2N - 1) /2 On Jan 11, 2:19 pm, Dipit Grover wrote: > @Lucifer :  I came up with a similar algorithm as yours but I dont > u

[algogeeks] Re: sort 2D array

2012-01-11 Thread Lucifer
@correction.. for ( int row = 0; row < *M*; ++row) On Jan 11, 1:56 pm, Lucifer wrote: > @All.. > > I have an idea... > > As we are looking for an in-place algo... > > Well, given the array, it actually mimics a min-heap.. not exactly a > binary tree heap but a heap wherein its subtrees share some

[algogeeks] Re: sort 2D array

2012-01-11 Thread Lucifer
@correction: /* basically either go down or go *right* in case adjustment is required... */ On Jan 11, 1:56 pm, Lucifer wrote: > @All.. > > I have an idea... > > As we are looking for an in-place algo... > > Well, given the array, it actually mimics a min-heap.. not exactly a > binary tree heap b

[algogeeks] Re: sort 2D array

2012-01-11 Thread Lucifer
@All.. I have an idea... As we are looking for an in-place algo... Well, given the array, it actually mimics a min-heap.. not exactly a binary tree heap but a heap wherein its subtrees share some nodes... Now the point being that... say we select any index pair (i,j), we know for the submatrix

[algogeeks] Re: Sort problem

2011-08-31 Thread Ankuj Gupta
Bitonic sort On Aug 31, 11:26 am, bharatkumar bagana wrote: > while increasing ... we have to use insertion sort which is in place algo .. > while decreasing... any way that is sorted one .. so no need to maintain ... > But it takes O(n^2) time .. > > On Wed, Aug 31, 2011 at 1:58 AM, Navneet Gupt

[algogeeks] Re: Sort IT

2011-08-11 Thread Dave
@Surender: Yes. Actually, I'm converting a[i]-1 into radix N. The most significant digit is (a[i]-1)/N, and the least significant digit is (a[i]-1)%N. You are right that the lsd should be before the msd. Thanks. Dave On Aug 11, 8:44 am, surender sanke wrote: > @dave, ur converting array values i

Re: [algogeeks] Re: Sort IT

2011-08-11 Thread surender sanke
@dave, ur converting array values into baseN and doing radix? then every time there will be N*N = 100(baseN). i think ur code doesn't works as ur checking against msd first(/) , then lsd(%) we need to exchange these operations, then it works fine. surender On Wed, Aug 3, 2011 at 3:55 PM, Dave wro

[algogeeks] Re: Sort IT

2011-08-03 Thread Dave
@Arun: Look up "Radix sort" and then read the comments in the code. Dave On Aug 3, 4:23 am, Arun Vishwanathan wrote: > yes dave it wud be better if u cud post an explanation of what u r doing in > each step..thanks > > > > On Wed, Aug 3, 2011 at 6:51 AM, payel roy wrote: > > @Dave, > > Can you

[algogeeks] Re: Sort IT

2011-08-03 Thread Dave
@Payel: Look up "Radix sort" and then read the comments in the code. Dave On Aug 2, 11:51 pm, payel roy wrote: > @Dave, > Can you please explain the algo? It's getting very difficult to understand > the code .. > > On 3 August 2011 01:14, Dave wrote: > > > > > @Pankaj: Assuming generously that

Re: [algogeeks] Re: Sort IT

2011-08-03 Thread Arun Vishwanathan
yes dave it wud be better if u cud post an explanation of what u r doing in each step..thanks On Wed, Aug 3, 2011 at 6:51 AM, payel roy wrote: > @Dave, > Can you please explain the algo? It's getting very difficult to understand > the code .. > > > On 3 August 2011 01:14, Dave wrote: > >> @Pank

Re: [algogeeks] Re: Sort IT

2011-08-02 Thread payel roy
@Dave, Can you please explain the algo? It's getting very difficult to understand the code .. On 3 August 2011 01:14, Dave wrote: > @Pankaj: Assuming generously that by N^2 you mean N*N instead of N > exclusive-or 2, your very first statement is already O(N^2), as it > will take that long just t

[algogeeks] Re: Sort IT

2011-08-02 Thread Dave
@Pankaj: Assuming generously that by N^2 you mean N*N instead of N exclusive-or 2, your very first statement is already O(N^2), as it will take that long just to set the array to zero. Here is a radix sort to sort an array x[N] containing values from 1 to N*N in O(N): int a[N], b[N], i; // initia

[algogeeks] Re: Sort IT

2011-08-02 Thread Agyat
absolutely correct dudethat was the way i read in clrs in radix sort chap On Aug 2, 4:50 pm, Harshit Kapoor wrote: > I think that we can do it by first passing through an array once and convert > all the interger to the base N in O(N). Since all elements are in the range > 1 to N^2 they can h

Re: [algogeeks] Re: Sort - Consecutive Array in O(n)

2011-07-09 Thread Anantha Krishnan
If the range is (0,n) then we can solve in O(n) TC and O(1) SC. int checkconsequtive(int a[],int n){ if(n<1) return 0; int min=a[0]; int max=a[0]; int i=0; for(i=1;imax) max=a[i]; } if(max-min+1!=n) return 0; for(i=0;i wrote: > > a) F

[algogeeks] Re: Sort - Consecutive Array in O(n)

2011-07-06 Thread Gaurav Tyagi
a) Find min(A). - O(n) b) Find max(A) - O(n) c) Calculate sum of natural numbers starting from min(A) to max(A) - O(n) d) Calculate sum of all numbers in the array. - O(n) e) If sum in step c) is not same as sum in step d), then elements are not consecutive. If the sum is same, then they are conse

Re: [algogeeks] Re: Sort - Consecutive Array in O(n)

2011-07-05 Thread Ganga Kameswaran
@sunny I dont understand the final checking part..Can u pls explain. On Sun, Jul 3, 2011 at 5:48 AM, Gene wrote: > You can use a count sort, but you need an array to store the counts. > The oppilas algorithm needs only constant extra storage. > > On Jun 30, 7:23 am, hary rathor wrote: > > can

[algogeeks] Re: Sort - Consecutive Array in O(n)

2011-07-02 Thread Gene
You can use a count sort, but you need an array to store the counts. The oppilas algorithm needs only constant extra storage. On Jun 30, 7:23 am, hary rathor wrote: > can we not use count sort because of O(n) .? -- You received this message because you are subscribed to the Google Groups "Algo

Re: [algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-30 Thread hary rathor
can we not use count sort because of O(n) .? -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.co

[algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-29 Thread Gene
I was responding to oppilas. His use of the formula N(N+1)/2 really doesn't help here. Hashing will work fine, but it's not the simplest or most efficient way. Because you're testing for consecutive integers, it makes more sense to use an array(min .. max) of booleans to test for duplicates rather

Re: [algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-29 Thread sunny agrawal
can't we directly hash the values at a[i] % N, if value is Negative hash to (A[i]%N) + N if two values hash to same places -Not consecutive But still we can have a problem like N = 2 and a[] = {1,4} because of hash value of values in the array may be consecutive but not the actual values so af

Re: [algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-29 Thread Aakash Johari
Please read it again. Hashing would also help in the case of duplicates. On Wed, Jun 29, 2011 at 9:16 AM, Gene wrote: > Your algorithm is good, but the first part doesn't help you because > duplicates are allowed. > > Here is code that does what you say: > > #include > > int main(void) > { > i

[algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-29 Thread Gene
Your algorithm is good, but the first part doesn't help you because duplicates are allowed. Here is code that does what you say: #include int main(void) { int a[] = { 6, 2, 4, 8, 7, 3, 5 }; int n = sizeof a / sizeof a[0]; int i, t, min, max, tmp; min = max = a[0]; for (i = 1; i < n;

[algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-28 Thread JohariツAakash
So, if the space doesnt matter. We can have an array A for hashing. So first we will find the minimum element in array suppose M. and in the other traversal of array, we will calculate for each element Ai in array Ai + (-M). So if it exceeds N then elements are not consecutive and other check that

Re: [algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-25 Thread oppilas .
Divye Thanks for the link. Quoting the top answer from there. "Under the assumption numbers less than one are not allowed and there are no duplicates, there is a simple summation identity for this - the sum of numbers from 1 to m in increments of 1 is (m * (m + 1)) / 2. You can then sum the array

Re: [algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-25 Thread DK
@Chinna: Your algorithm is simple quicksort with partition selection using medians. O(n log n) worst case. @Varun: You cannot prove that your algorithm will work for all cases. Hence, claiming a worst case bound of O(n) is incorrect. http://stackoverflow.mobi/question177118_Algorithm-to-determi

Re: [algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-25 Thread varun pahwa
1 thing i forgot to mention in my above post that at first i will also check max - min + 1 must be equal to n. then only move further else the array will not be consecutive after sort. I think it will give correct output. please tell if any counter example. On Sat, Jun 25, 2011 at 2:29 AM, pacific

Re: [algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-25 Thread pacific :-)
My approach : 1. Find the median. 1.5 Check if the median is min + (max - min ) / 2. 2. Partition the array into two sub arrays using the partition function of quicksort. 3. Check if the subarrays also satisfy the constraint. Complexity : T(n) = 2 T(n/2) + O(1) :: O(nlogn) On Sat, Jun 25, 20

Re: [algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-24 Thread varun pahwa
will this work. n size of array. cal (a[i] - min(arr) + 1). now cal sum of a[i], cal square sum of array as (a[i] * a[i]) , cal cube sum of array as (a[i] * a[i] * a[i]). now if array elements are consecutive then sum must be n * (n + 1) / 2. square sum must be (n * (n + 1) * (2n + 1) )/ 6 and cube

[algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-24 Thread Adarsh
I think I got an work around for this if number of elements are not odd why not make them odd :) I variation to my prev algo int n = A.size(); for (int i=0; ihttp://groups.google.com/group/algogeeks?hl=en.

Re: [algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-24 Thread sunny agrawal
@adarsh no it will Fails for both even and odd no of elemets a[] = {2,2,2,4,6,6,6} seems like we need to check for the presence of each no between min to max using a good hashing approach. On Sat, Jun 25, 2011 at 11:20 AM, Adarsh wrote: > Missed that... also, my method seems to work only if num

[algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-24 Thread Adarsh
Missed that... also, my method seems to work only if number of elements are odd. -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to a

Re: [algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-24 Thread sunny agrawal
@Adarsh fails on this a[] = {2,2,2,6,6,6} On Sat, Jun 25, 2011 at 10:54 AM, Adarsh wrote: > int n = A.size(); > for (int i=0; itotal += A[i]; > findMinMax(A[1...n]); > > int mean = (max+min)/2; > if ((total - n*mean) == 0) >printf("consecutive\n"); > else >printf("not consecutive\n")

[algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-24 Thread Adarsh
int n = A.size(); for (int i=0; ihttp://groups.google.com/group/algogeeks?hl=en.

Re: [algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-24 Thread oppilas .
Gene is correct :) Counter example {1, 2, 2, 5, 5} See method 3 here http://geeksforgeeks.org/?p=11516 On 6/25/11, Gene wrote: > Nice idea, but unfortunately doesn't work. The XOR only contains > parity information. So just pick two values in the range and a low > order bit where they're differe

[algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-24 Thread Gene
Nice idea, but unfortunately doesn't work. The XOR only contains parity information. So just pick two values in the range and a low order bit where they're different. Then swap the bits. 2 xor 3 xor 4 xor 5 = 0 Pick 3 and 4 and swap the lsb, which gives 2 and 5. So we have 2 xor 2 xor 5 xor 5

Re: [algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-24 Thread Piyush Sinha
I have a solution that will do the job in O(n) time but will require three variablesbut this solution won't work if the array contains -ve numbers. * int findrepeat(int a[],int n) { int i,xor = 0; int min = findmin(a,n); int max = findmax(a,n); if((max-min+1)!=n) re

[algogeeks] Re: Sort - Consecutive Array in O(n)

2011-06-24 Thread ross
One solution would be to : check if max-min = N and that all elements are unique in the array. However, this may require space complexity.. Looking for a better solution. On Jun 25, 12:44 am, ross wrote: > Given an array, A, find if all elements in the sorted version of A are > consecutive in les

[algogeeks] Re: sort the array

2011-06-23 Thread sankalp srivastava
People should not just come over here , write one word and go .If you cannot explain you're logic with an example , means you haven't even tried the problem .You just want to boast you're adroit .In place merging of two sorted is not an easy problem . . On Jun 22, 9:48 pm, ankit mehta wrote: >

[algogeeks] Re: sort the array

2011-06-22 Thread ankit mehta
Yes thats what I am saying that algorithm presented by Mr. Navneet wont work. On Jun 22, 9:40 pm, Apoorve Mohan wrote: > @ankit: we need an inplace algorithm :) -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send ema

Re: [algogeeks] Re: sort the array

2011-06-22 Thread Apoorve Mohan
@ankit: we need an inplace algorithm :) -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. Fo

Re: [algogeeks] Re: sort the array

2011-06-22 Thread Ankit Agarwal
This problem can also be done by using Merging function as in the merge sort. 1. Copy the sorted elements of the first half in one array (arr L) and second half in another (arr R). Original array N. 2. count vary from 1 to n. if (L[i] < R[j] ) { N[count] = L[i], i++} else { N[count] = R[j]

[algogeeks] Re: sort the array

2011-06-22 Thread ankit mehta
In step 2 it should me m++ instead of n++ and similarly in step 3 n+ +. But still I dont think it will work if we carry out these iterations on this particular array. It will return , what I think: 1 2 3 5 10 4 8 12. Please correct me if I am wrong. On Jun 22, 7:50 pm, Navneet Gupta wrote: > Let

Re: [algogeeks] Re: sort the array

2011-06-22 Thread oppilas .
On Wed, Jun 22, 2011 at 8:38 PM, oppilas . wrote: > > > On Wed, Jun 22, 2011 at 8:20 PM, Navneet Gupta wrote: > >> Let the array elements be 2,3,5,10 & 1,4,8,12. >> >> Have two index variables m and n. Intially m will point to 2 and n to 1. >> >> 1. Compare the elements in m and n. >> 2. If elem[m

Re: [algogeeks] Re: sort the array

2011-06-22 Thread oppilas .
On Wed, Jun 22, 2011 at 8:20 PM, Navneet Gupta wrote: > Let the array elements be 2,3,5,10 & 1,4,8,12. > > Have two index variables m and n. Intially m will point to 2 and n to 1. > > 1. Compare the elements in m and n. > 2. If elem[m] > elem[n] swap, increment n > *I think it should be increment

Re: [algogeeks] Re: sort the array

2011-06-22 Thread Navneet Gupta
Let the array elements be 2,3,5,10 & 1,4,8,12. Have two index variables m and n. Intially m will point to 2 and n to 1. 1. Compare the elements in m and n. 2. If elem[m] > elem[n] swap, increment n 3. else increment m and go to step 1. 4. end if m becomes the starting value of n or n reaches end

Re: [algogeeks] Re: sort the array

2011-06-22 Thread Algoose chase
Reverse the 2nd part of the Array so that they are sorted in descending order. Then apply bitonic sort On Wed, Jun 22, 2011 at 2:34 PM, ross wrote: > @himanshu: I dont think, the approach works, in present form. > in place merge sort or insertion sort is fine. > Test with, 12 13 19 16 and 0 20

[algogeeks] Re: sort the array

2011-06-22 Thread ross
@himanshu: I dont think, the approach works, in present form. in place merge sort or insertion sort is fine. Test with, 12 13 19 16 and 0 20 10 14 as 2 parts of the array. On Jun 22, 8:42 am, Sriganesh Krishnan <2448...@gmail.com> wrote: > ya...we can do it in O(n) n time!!! > nice question! > >

Re: [algogeeks] Re: sort in minimum cost

2011-04-29 Thread Anurag Sharma
This seems longest increasing subsequence problem to me.. Thanks, Anurag On Mon, Apr 25, 2011 at 9:31 PM, snehal jain wrote: > few eg > input > 4 7 12 3 1 > output 4 7 12 > cost: 4 by removing 3 n 1 > > eg 2 > > 6 3 5 7 12 4 > o/p 3 3 5 7 12 > cost 7 by decrementing 6 by 3 and removing 4 > > eg

Re: [algogeeks] Re: sort in minimum cost

2011-04-29 Thread Harish U
Given the list, you would never want to decrement the last element as you want it to be the maximum. so either retain or remove the last element Lets consider the Minimum cost among the sequence i to j as Cost[i..j] So if you remove the element j, you add j to the cost Cost[i..j] = Min{ Min(c

Re: [algogeeks] Re: sort in minimum cost

2011-04-26 Thread snehal jain
@above you cant increment On Tue, Apr 26, 2011 at 3:48 PM, Naveen Agrawal wrote: > @snehal jain > > 4 9 8 7 8 >> o/p 4 7 7 7 8 >> cost 3 by decrementing 9 n 8 > > > Yes, now question is clear but your last example is incorrect. > > > 4 9 8 7 8 > o/p 4 8 8 8 8 > cost 2 = decrementing (9 to 8) + in

Re: [algogeeks] Re: sort in minimum cost

2011-04-26 Thread Naveen Agrawal
@snehal jain 4 9 8 7 8 > o/p 4 7 7 7 8 > cost 3 by decrementing 9 n 8 Yes, now question is clear but your last example is incorrect. 4 9 8 7 8 o/p 4 8 8 8 8 cost 2 = decrementing (9 to 8) + incrementing (7 to 8) -- You received this message because you are subscribed to the Google Groups "Al

Re: [algogeeks] Re: sort in minimum cost

2011-04-25 Thread snehal jain
few eg input 4 7 12 3 1 output 4 7 12 cost: 4 by removing 3 n 1 eg 2 6 3 5 7 12 4 o/p 3 3 5 7 12 cost 7 by decrementing 6 by 3 and removing 4 eg 3 4 9 8 7 8 o/p 4 7 7 7 8 cost 3 by decrementing 9 n 8 i hope its clear now.. On Mon, Apr 25, 2011 at 9:16 PM, hary rathor wrote: > just tell me >

Re: [algogeeks] Re: sort in minimum cost

2011-04-25 Thread hary rathor
just tell me what is input and what will the output. atleast 3 example -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algogeeks+

[algogeeks] Re: sort in minimum cost

2011-04-25 Thread Don
I don't understand your example. If the input has only one "3", and the output has more than one, you have not sorted the elements. Do you mean alter the elements to make the array non-decreasing? Don On Apr 25, 4:21 am, snehal jain wrote: > Given n elements, sort the elements. Here, only one ope

[algogeeks] Re: Sort array with two subparts sorted

2011-04-13 Thread sravanreddy001
@ligerdave.. actually.. the problem is, O(n) is correct, but, this will again space dependent where it is again O(n).. so.. it has to be done in constant space.. no additional space.. so.. just swapping is allowed.. what's the best time complexity for this? -- You received this message becaus

[algogeeks] Re: Sort array with two subparts sorted

2011-04-13 Thread ligerdave
Why make this overcomplicated? There isn't a merge sort needed if two arrays were already sorted. It takes only O(n). Each time, you compare the leading elements and remove the smaller one and store it in a new array. On Apr 12, 6:33 pm, Carl Barton wrote: > Very interesting link! > > As we on

Re: [algogeeks] Re: Sort array with two subparts sorted

2011-04-12 Thread Carl Barton
Very interesting link! As we only need to perform one merge we should be able to modify it to run in O(n) time? In a similar style as a strand sort? On 12 April 2011 22:55, hary rathor wrote: > > http://thomas.baudel.name/Visualisation/VisuTri/inplacestablesort.html > > > take a glance on this

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