Re: [algogeeks] Re: time complexity of gcd euclid algo(recursive)

2012-11-23 Thread Pralay Biswas
@Dave: Could you please correct me if am wrong here. 1) So we are looking out for the worst case, and that happens when m and n are consecutive Fibo numbers, being mutually prime to reach other. 2) Its taking 5 iterations to reduce the number of digits in the smaller of m and n, by one. Assuming

Re: [algogeeks] Re: time complexity of gcd euclid algo(recursive)

2012-11-23 Thread Dave
@Pralaybi: You've got it right. Since h is proportional to the log of the smaller number, we also can say that the complexity is O(log^2 (smaller number)). Dave On Friday, November 23, 2012 2:09:01 PM UTC-6, pralaybi...@gmail.com wrote: @Dave: Could you please correct me if am wrong here.

Re: [algogeeks] Re: time complexity of gcd euclid algo(recursive)

2012-11-18 Thread Dave
@Bharat: See, e.g., http://en.wikipedia.org/wiki/Euclidean_algorithm#Algorithmic_efficiency. Dave On Sunday, November 18, 2012 12:03:33 AM UTC-6, bharat wrote: @ Dave : can u pls explain the solution u gave . How can u say fibnocci sequence produces worst case ? On Fri, Nov 16, 2012 at

Re: [algogeeks] Re: time complexity of gcd euclid algo(recursive)

2012-11-17 Thread Shruti Gupta
Don, thanks for the solution, Can u pls explain how a+b gets reduced by atleast 25% On Fri, Nov 16, 2012 at 3:42 AM, Don dondod...@gmail.com wrote: Tail recursion is no different than a loop, so the complexity is the same as an iterative solution like this: int gcd(int a, int b) // For ab

Re: [algogeeks] Re: time complexity of gcd euclid algo(recursive)

2012-11-17 Thread bharat b
@ Dave : can u pls explain the solution u gave . How can u say fibnocci sequence produces worst case ? On Fri, Nov 16, 2012 at 11:15 AM, Shruti Gupta fundooshr...@gmail.comwrote: Don, thanks for the solution, Can u pls explain how a+b gets reduced by atleast 25% On Fri, Nov 16, 2012 at 3:42

Re: [algogeeks] Re: time complexity of gcd euclid algo(recursive)

2012-11-16 Thread bharat b
@Don : how can u say that a+b reduces by atleast 25% .. in each iteration b won't be changed in (a+b). b just shifted to a. a gets changed to a%b. == a+b will become at max 2b-1 .. we can't deduce any relation between a+b to 2b-1. why do we need the % of reduction on (a+b) in each iteration ?

[algogeeks] Re: time complexity of gcd euclid algo(recursive)

2012-11-16 Thread Don
Sorry, I said that wrong. a+b is reduced by 25% over any TWO iterations. Look at these cases 2a = b : b % (a % b) a and 2*a = b, so b is decreased by at least half, so a+b decreased by at least 25% a b : b will become b-a, which is less than b/2, decreasing a+b by at least 25%. a==b :

[algogeeks] Re: time complexity of gcd euclid algo(recursive)

2012-11-16 Thread sonesh
you see, in each step of recursion, the number of digits in *n* is decrease by one(at least in worst case), so the complexity you can decide. On Tuesday, November 13, 2012 3:34:06 PM UTC+5:30, Shruti wrote: hi Can anyone help me find out the time complexity of recursive gcd algorithm

[algogeeks] Re: time complexity of gcd euclid algo(recursive)

2012-11-16 Thread Dave
@Sonesh: Not so. The worst case for Euclid's algorithm is when the numbers are consecutive Fibonacci numbers. So (89,55) -- (55,34) -- (34,21) -- (21,13) -- (13,8) -- (8,5), so it took 5 steps to reduce the number of digits of the first number from 2 to 1. Asymptotically, the number of digits

[algogeeks] Re: time complexity of gcd euclid algo(recursive)

2012-11-15 Thread Don
Tail recursion is no different than a loop, so the complexity is the same as an iterative solution like this: int gcd(int a, int b) // For ab { while(1) { int c = a % b; if (!c) return b; a = b; b = c; } } The complexity is log(a) + log(b) because

Re: [algogeeks] Re: Time Complexity Ques

2012-01-17 Thread atul anand
answer to this post has not yet been answered ...i.e abt complexity. seems log(n) to me.. correct me if i am wrong. On Mon, Jan 16, 2012 at 8:53 AM, Gene gene.ress...@gmail.com wrote: I'm sorry for not being specific. I meant it doesn't converge for all roots, e.g. cube root. On Jan 15,

Re: [algogeeks] Re: Time Complexity Ques

2012-01-17 Thread sravanreddy001
@atul: on the first look, even I thought the same.. O(log N).. and this is may be true for the given precision. *[-- the following may not be related to given qn.] -- but.. can u comment on this view point..* but.. I am thinking that, the complexity is dependent on the level of precision

[algogeeks] Re: Time Complexity Ques

2012-01-15 Thread Gene
To find sqrt(a), this is equivalent to Newton's Method with f(x)=x^2 - a. Newton is: x_{i+1} = x_i + f'(x_i) / f'(x_i). So you have x_{i+1} = x_i + (x_i^2 - a) / (2 x_i) = (x + a/x) / 2, which is just what the Babylonian method says to do. Newton's method roughly doubles the number of

[algogeeks] Re: Time Complexity Ques

2012-01-15 Thread Dave
@Gene: Actually, Newton's Method for sqrt(a), where a 0, also sometimes called Heron's Method, converges for every initial guess x_0 0. This is not true generally for Newton's Method, but it is true for Newton's Method applied to f(x) = x^2 - a. Dave On Jan 15, 5:39 pm, Gene

[algogeeks] Re: Time Complexity Ques

2012-01-15 Thread Gene
To find sqrt(a), this is equivalent to Newton's Method with f(x)=x^2 - a. Newton is: x_{i+1} = x_i + f'(x_i) / f'(x_i). So you have x_{i+1} = x_i + (x_i^2 - a) / (2 x_i) = (x + a/x) / 2, which is just what the Babylonian method says to do. Newton's method roughly doubles the number

[algogeeks] Re: Time Complexity Ques

2012-01-15 Thread Gene
I'm sorry for not being specific. I meant it doesn't converge for all roots, e.g. cube root. On Jan 15, 10:18 pm, Dave dave_and_da...@juno.com wrote: @Gene: Actually, Newton's Method for sqrt(a), where a 0, also sometimes called Heron's Method, converges for every initial guess x_0 0. This

[algogeeks] Re: Time Complexity

2011-11-22 Thread Gene
Hi Atul, You're correct. I was commenting on the original poster's words I guess its NlogN for balanced tree as it is traversing N nodes for H times, which is not correct. The general result is that the run time will be O(N) for any balance rule where the ratio R of left to right subtree size

Re: [algogeeks] Re: Time Complexity

2011-11-21 Thread atul anand
@Gene : i guess you are considering balanced tree. what if the tree is left skewed or right skewed . then height of thee will ne H=No. of node. so we will get :- 1+2+3+4H so recurrence will be T(n) = T(n-1) + O(n) hence complexity will be O(N^2) correct me if i am missing somthing.

[algogeeks] Re: Time Complexity

2011-11-20 Thread Gene
My advice is don't guess. Do the math. To print level L of a perfectly balanced tree, you will traverse 2^L -1 nodes. The outer loop that prints levels 1 .. H will therefore traverse sum_{L=1..H} (2^L - 1) = 1 + 3 + 7 + ... 2^H - 1 Let N = 2^H - 1 be the number of nodes in the tree. Then

[algogeeks] Re: Time Complexity

2011-11-19 Thread ((** VICKY **))
Its level order traversal but its O(n^2) u search entire tree to check if the nodes level is i (say 0= i = height). i guess can use stack or queue to get O(n) complexity On Nov 19, 2:58 pm, shady sinv...@gmail.com wrote: this doesn't seem like level order printing, because you are simply

[algogeeks] Re: Time Complexity

2011-11-19 Thread Ankuj Gupta
Try it once. It is for level order only in dfs way On Nov 19, 2:58 pm, shady sinv...@gmail.com wrote: this doesn't seem like level order printing, because you are simply printing the tree starting with the children as the root node. On Sat, Nov 19, 2011 at 12:57 PM, Ankuj Gupta

[algogeeks] Re: Time Complexity

2011-11-19 Thread Ankuj Gupta
I guess its NlogN for balanced tree as it is traversing N nodes for H times ie the height of tree which is logN for balanced and N for skewed tree. So it should be Nlogn and N^2 On Nov 20, 9:27 am, tech coder techcoderonw...@gmail.com wrote: @ sravanreddy001 complexity is O(N^2) whether tree is

[algogeeks] Re: Time complexity

2011-09-21 Thread siva viknesh
somebody plz reply... On Sep 21, 10:53 pm, sivaviknesh s sivavikne...@gmail.com wrote: for(i=0;in;i++)     for(j=0;ji*i;j++)         for(k=0;kj;k++)             sum++; Is it    n^5 log n . n * (n^2 log n) * (n^2 log n) ??? correct me if i m wrong?  also anybody can tell some easy

[algogeeks] Re: Time complexity

2011-09-21 Thread Dave
@Siva: Work from the inside out, using the identities sum from i = 1 to n (i) = n*(n+1)/2 sum from i = 1 to n (i^2) = n*(n+1)*(2*n+1)/6 sum from i = 1 to n (i^3) = n^2*(n+1)^2/4 sum from i = 1 to n (i^4) = n^5/5 + n^4/2 + n^3/3 - n/30 Dave On Sep 21, 10:03 pm, siva viknesh

[algogeeks] Re: Time complexity

2011-09-21 Thread siva viknesh
@Dave ... thanks dude.So it should be O(n^5) .. am i right ?? On Sep 22, 8:19 am, Dave dave_and_da...@juno.com wrote: @Siva: Work from the inside out, using the identities sum from i = 1 to n (i) = n*(n+1)/2 sum from i = 1 to n (i^2) = n*(n+1)*(2*n+1)/6 sum from i = 1 to n (i^3) =

[algogeeks] Re: Time complexity

2011-09-21 Thread Ankuj Gupta
yes it is n^5 On Sep 22, 8:53 am, siva viknesh sivavikne...@gmail.com wrote: @Dave ... thanks dude.So it should be O(n^5) .. am i right ?? On Sep 22, 8:19 am, Dave dave_and_da...@juno.com wrote: @Siva: Work from the inside out, using the identities sum from i = 1 to n (i) =

[algogeeks] Re: Time complexity - is anybody bothered about it anyway?

2010-08-22 Thread R.ARAVINDH
@asutosh:: all ur efforts 2 write some code wud be worthless if it cant work for some inputs...if it can , then no one does bother about time complexity. since it doesn for large i/ps v hav 2 write some efficient code (although i agree wid u dat its painful :P ) On Aug 17, 9:45 pm, Dave

Re: [algogeeks] Re: Time complexity - is anybody bothered about it anyway?

2010-08-22 Thread Manjunath Manohar
can anyone say how to calculate the complexity of a recurrence relation -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to

[algogeeks] Re: Time complexity - is anybody bothered about it anyway?

2010-08-17 Thread Dave
For 30 years, I developed mathematical software (linear equation solvers, eigenvalue routines, fast Fourier transforms, etc.) on a wide variety of high-performance computers with interesting architectures. For those, the optimal-order algorithms are well known. My principal goal was to implement a

[algogeeks] Re: Time complexity

2007-06-12 Thread Adrian Godong
You should provide the limit/point where T(m) is constant. Say T(1) = 1, or something else. Only then we can calculate the time complexity. On 6/12/07, Phanisekhar B V [EMAIL PROTECTED] wrote: How can i calculate the time complexity of the following problem? T(m) = 2T(m/2) + O(

[algogeeks] Re: Time complexity

2007-06-12 Thread Phanisekhar B V
Adiran, Yes u r right. Let T(1) = 1. On 6/12/07, Adrian Godong [EMAIL PROTECTED] wrote: You should provide the limit/point where T(m) is constant. Say T(1) = 1, or something else. Only then we can calculate the time complexity. On 6/12/07, Phanisekhar B V [EMAIL PROTECTED] wrote: How

[algogeeks] Re: Time complexity

2007-06-12 Thread Ray
I think it's O(n). Because the order of squareroot((log log m) / (log m)) is less than m's. T(n) = a T (n/b) + f(n) 1. O(n ^(lgb/lga) ) O(f(n)) T(n) = O(n ^(lgb/lga)) 2. O(n ^(lgb/lga) ) = O(f(n)) T(n) = O(lg(n)*f(n)) 3. O(n ^(lgb/lga) ) O(f(n)) T(n) = O(f(n)) The problem fits the 1st

[algogeeks] Re: Time complexity

2007-06-12 Thread Phanisekhar B V
Hi Ray, Can u do this without using Master theorem? I also need to fine the time complexity of problems like: T(m) = 2T(m/2) + O( m^2 * squareroot((log log m) / (log m)) ) basically i need a solution without using master theorem. Regards, Phani On 6/12/07, Ray [EMAIL

[algogeeks] Re: Time complexity

2007-06-12 Thread Mayur
Don't know if the O-notation is also defined for complex functions. Well, if it isn't, here's a possibility: - (please correct me if I am wrong here.. ) For sqrt( x ) to be real, x needs to be 0 = log(log(m)) / log(m) 0 But we also know that log(m) log(log(m)) for all values of m for which

[algogeeks] Re: time complexity of algorithms

2006-12-17 Thread jack wang
I wonder the average case here means the average successful searching case or average unsuccessful searching case or the total average searching case? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Algorithm

[algogeeks] Re: time complexity of algorithms

2006-12-17 Thread Tanmoy Sarkar
hello look the best case of circular queue is 0(1) and worst case is 0(n) so avg. case should be between these two so if n+1/2 is avg case then also avg. case will be then 0(n). plz check it and may be i am wrong bye On 12/16/06, programming [EMAIL PROTECTED] wrote: programming

[algogeeks] Re: time complexity of algorithms

2006-12-15 Thread Mayur
1.) If you're talking about search using a tree with each node having degree 4, then the best-case complexity is indeed O(1). Why, the first node (the root) could be the one that you're looking for. 3.) Yes indeed. Since, your tree doesn't seem to have any branching logic (like a BST does), the

[algogeeks] Re: time complexity of algorithms

2006-12-15 Thread programming
programming wrote: Thanks for the advice, i think i am right about the circular queue been a(n)=n+1/2, you agree? Is this also the average case for a tree of degree(4)? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google