Re: [algogeeks] BST Question

2010-10-24 Thread Praveen Baskar
oh ya thanks now i got it On Sun, Oct 24, 2010 at 9:54 AM, preetika tyagi preetikaty...@gmail.comwrote: @Praveen- In this case, we will not ignore the right subtree of the root (-10, which is less than zero) while traversing the tree. On Sat, Oct 23, 2010 at 9:06 PM, Praveen Baskar

[algogeeks] Re: Algorithm to find whether any 3point on the same line

2010-10-24 Thread Dave
@Ravindra: Can you explain the algorithm for step 3 in more detail? I don't yet see how you do it in O(n^2), since it seems to me that comparing one A[i,j] to all the A[j,k] is already O(n^2). What am I missing? Dave On Oct 24, 12:05 am, ravindra patel ravindra.it...@gmail.com wrote: Can be

[algogeeks] Re: Algorithm to find whether any 3point on the same line

2010-10-24 Thread Avik Mitra
We can do the following in 2-D plane where the pints are given in the form of (x.y). For each selection of three points do the following: Find the area of the triangle of the three points. Let it be A. If A is zero then Print Existence of Co-linear points Break. This can be achieved in C(n,3)

[algogeeks] Re: BST Question

2010-10-24 Thread Avik Mitra
The suggestion will work if the root is known to have entry equal to zero. (Even it is less than 0, there is a chance that a negative an reside in right sub-tree whose value is 0 but greater than the negative value of the root). If the entry of the root is zero then we can do the inorder

[algogeeks] Re: Binary Tree

2010-10-24 Thread Avik Mitra
We can do the following. We associate a variable with each of the node. let it be called level. We now do BFS on the tree. Whenever we visit a node we do the following: node.level = blackNeigbor.level + 1. Now we again do a BFS to find the number of nodes in each level. -- You received this

[algogeeks] Re: how would you find the integer pairs which sum to m in o(n) time complexity

2010-10-24 Thread Avik Mitra
We can follow an algorithm described below. Set found:= FALSE For each number n belong to array A.and until found != TRUE For each number k in A not equal to n, do: if k+n == m then output The pairs are n and k Set found:=TRUE. Break. The running time will be of

[algogeeks] Re: Finding parallel edges in graph

2010-10-24 Thread Avik Mitra
Consider the following adjacency-matrix representation of a graph, R(V,E). Let there be n number of vertices. So we create n*n matrix G[1..n] [1..n]. Initially set G[i][j]=0 for all 1= i,j =n. This operation will take O(V). For each edge e of R let (a,b) be the adjacent vertices, set G[a] [b]

Re: [algogeeks] Re: Algorithm to find whether any 3point on the same line

2010-10-24 Thread Meng Yan
for the 3th step, for i=1 to n for j=i+1 to n for k=j+1 to n compare A[i,j] and A[j,k] if A[i,j]==A[j,k] find i,j,k are collinear. so we should need O(n^3), is it right? On Sun, Oct 24, 2010 at 1:05 AM, ravindra patel ravindra.it...@gmail.comwrote: Can be done in O(n^2) time

Re: [algogeeks] Re: Algorithm to find whether any 3point on the same line

2010-10-24 Thread ravindra patel
@Dave I was wrong. It can't be done in O(n^2) time. The best we can do is sort each row like you suggested in your other post. That will still be O((n^2)logn). Thanks, - Ravindra On Sun, Oct 24, 2010 at 7:06 PM, Meng Yan mengyan.fu...@gmail.com wrote: for the 3th step, for i=1 to n for

[algogeeks] Re: 10 most repeating words

2010-10-24 Thread ligerdave
@Dave I hear ya. Im just saying in general, you would wanna have an algorithm for all cases. of coz, in this case, if the RAM isn't a consideration and heapsort is what @Vinay wants, i guess we are coming up w/ one like that. again, in general, you don't wanna have one version of program for king

Re: [algogeeks] Re: Yahoo coding round question

2010-10-24 Thread ravindra patel
@ Kishen So lets say you have 100 parallel processors and you are given an array of 100 elements, then the loop will execute in 1 clock. Now lets say on the same machine you are given a problem array of 1 million elements. So how many clocks are you gonna consume, assuming all your 100 processors

Re: [algogeeks] Re: Yahoo coding round question

2010-10-24 Thread ravindra patel
It has nothing to do with time complexity. My bad. Wrong choice of words. So in the PRAM model you can say the time complexity is O(1), a pure theoretical concept. But the cost still remains O(n), isn't it. I guess now onwards we'll have to specifically ask interviewers whether they are asking

Re: [algogeeks] Re: how would you find the integer pairs which sum to m in o(n) time complexity

2010-10-24 Thread preetika tyagi
I think we can sort the elements first and then start scanning from both ends of the array. All the pairs can be found this way and the complexity will be O(nlogn). On Sun, Oct 24, 2010 at 6:08 AM, Avik Mitra tutai...@gmail.com wrote: We can follow an algorithm described below. Set found:=

Re: [algogeeks] Re: Yahoo coding round question

2010-10-24 Thread Saurabh Koar
@Mohit: What I understand that in your solution the sum and product array contains the sum and products of contiguous sub-array starting from 0 to i (index of array A). What happens when the expected sub array starts form an index other than 0? -- You received this message because you are

[algogeeks] Re: Yahoo coding round question

2010-10-24 Thread ligerdave
@ravindra agree! On Oct 24, 2:20 pm, ravindra patel ravindra.it...@gmail.com wrote: @ Kishen So lets say you have 100 parallel processors and you are given an array of 100 elements, then the loop will execute in 1 clock. Now lets say on the same machine you are given a problem array of 1

[algogeeks] Re: 10 most repeating words

2010-10-24 Thread Chi
The biggest weakness of the trie is the amount of space it wastes - chances are there will be runs of characters with a word only at the end, meaning a bunch of extra levels of the tree that aren't needed. The PATRICIA trie, or radix trie, attempts to address this by allowing the 'decision' at

Re: [algogeeks] Finding parallel edges in graph

2010-10-24 Thread Kishen Das
What will be the input for the graph? Kishen On Thu, Oct 21, 2010 at 5:22 AM, Algorithimist yogi15...@gmail.com wrote: Design an algorithm to determine whether a graph has any parallel edges in time proportional to E + V. -- You received this message because you are subscribed to the

Re: [algogeeks] Re: how would you find the integer pairs which sum to m in o(n) time complexity

2010-10-24 Thread MOHIT ....
@preetika : we can use hash table for O(n) complexity ..if array is not sorted .. i am looking for that answer... how should i make that hash table so that searching in hash table become O(1) complexity. -- You received this message because you are subscribed to the Google Groups Algorithm

Re: [algogeeks] Re: 10 most repeating words

2010-10-24 Thread Kishen Das
MapReduce is the best option . For the word count its explained here - http://en.wikipedia.org/wiki/MapReduce Interesting thing is that the Map step can easily be made parallel. Once again I request the members of this group to go through all the parallel constructs. ( Parallel sorting,

Re: [algogeeks] Re: Yahoo coding round question

2010-10-24 Thread Kishen Das
@Ravindra, Ligerdave You guys are all right. But with GPUs, you can literally have thousands of threads running in parallel. Again, my aim was not to prove that my O(n ^ 2) algorithm is O ( n) on a single processor system. It was more towards making the members of this group to think on the lines

Re: [algogeeks] Re: Yahoo coding round question

2010-10-24 Thread MOHIT ....
@saurabh koar : no it will give that sub array .. but kishan das solution is good... btw my code explanation is A: 2 4 356 PRODUCT:2 8 24 120 720 SUM 2 6 9 14 20 suppose i want sum 8 and product 15 make hash table for product array (in hashtable

[algogeeks] Re: 10 most repeating words

2010-10-24 Thread Chi
From Wikipedia: Thus the MapReduce framework transforms a list of (key, value) pairs into a list of values. This behavior is different from the functional programming map and reduce combination, which accepts a list of arbitrary values and returns one single value that combines all the values

Re: [algogeeks] Re: how would you find the integer pairs which sum to m in o(n) time complexity

2010-10-24 Thread preetika tyagi
@Mohit : Then insert all the elements in hashtable and scan the hashtable in O(n) time. While scanning each elements, you have to search for (sum-element) element in the hashtable (O(1) time). What do you think? On Sun, Oct 24, 2010 at 12:51 PM, MOHIT mohit...@gmail.com wrote: @preetika :