Re: [algogeeks] A binary tree question

2011-12-11 Thread atul anand
by zig-zag order means level order traversal ??? On Sun, Dec 11, 2011 at 6:22 AM, AMAN AGARWAL mnnit.a...@gmail.com wrote: Hi, Given a tree, in addition to the left and right pointer, it has a third pointer, that is set to NULL. Set the third pointer to a node, which will be the successor

[algogeeks] Re: convert a sorted DLL to bst

2011-12-11 Thread Lucifer
1) Get the count of nodes in the given DLL. Say its, n. 2) Call convert(0, n-1, headPtrToDLL); node* convert(int start, int end, node **head) { node * root = NULL; if (start end) return NULL; int mid = (start + end) / 2; node * left = convert(

Re: [algogeeks]

2011-12-11 Thread Lucifer
@Dheeraj The ans for 14532 should be 15234.. I am calculating using the above given algo to get to the ans: 1) 4 is the value where A[i] A[i+1] when scanned from the end. 2) The closest element grater than equal to 4 in the subarray 532 is 5. 3) Swap (4,5) : 14532 - 15432 4) Now, as we have

Re: [algogeeks] A binary tree question

2011-12-11 Thread WgpShashank
@atul zig-zag mean spiral traversal of tree e.g. alternate the level while traversing , if previous traversal is left to right , then next level will be right to left . @aman .quest has little ambiguity its says successor but ebvery nodes can have we can ore-order , inorder ,postorder

[algogeeks] Re: A binary tree question

2011-12-11 Thread Gene
You can do a zig-zag traversal of a tree by using 2 stacks in place of the 2 queues you'd use for level order traversal. As you do the zig- zag traversal, just keep track of the current and previous node visited and set previous-zznext = current at each visit. On Dec 11, 1:52 am, AMAN AGARWAL

[algogeeks] Re: convert a sorted DLL to bst

2011-12-11 Thread Gene
This is nice. There is also an article on how to do this iteratively with a stack: http://groups.google.com/group/comp.programming/msg/41f46b2801c4f84e This solution actually traverses a BST of any shape, tears it apart, and reassembles it as a perfectly balanced tree. However, it will also

[algogeeks] Re: finding duplicate set of paranthesis

2011-12-11 Thread Gene
We talked about the problem of removing as many parentheses as possible: http://groups.google.com/group/algogeeks/browse_thread/thread/26ce36ad34dce9dc/e8fb40ab2ba0ecc0 You didn't define duplicate. For (a*b)+c, the parens don't add any information. Should they be removed? The algorithm given

Re: [algogeeks] A binary tree question

2011-12-11 Thread AMAN AGARWAL
Hi, Suppose we have a binary search tree as 15,12,18,17,21,11,14 then O/P will be 15 12 18 21 17 14 11. so the successor of 15 is 12 the successor of 12 is 18 and so on. I hope now its clear. Regards, Aman. On Sun, Dec 11, 2011 at 6:26 PM, WgpShashank shashank7andr...@gmail.comwrote: @atul

Re: [algogeeks] Detect a loop with just head ptr given

2011-12-11 Thread rahul sharma
for linked we always have only head On Thu, Dec 8, 2011 at 11:40 PM, sayan nayak sayanna...@gmail.com wrote: @Himanshu: If I follow ur algo..then I have to remove the loop..Otherwise there will not be any head for the reversed linked-list. If u wanna say..First remove the loop,make it a

Re: [algogeeks] A binary tree question

2011-12-11 Thread atul anand
@Gene : if i am not wrong , level order traversal can be done using only 1 queuewhy 2 queue??? On Sun, Dec 11, 2011 at 9:53 PM, AMAN AGARWAL mnnit.a...@gmail.com wrote: Hi, Suppose we have a binary search tree as 15,12,18,17,21,11,14 then O/P will be 15 12 18 21 17 14 11. so the

Re: [algogeeks] A binary tree question

2011-12-11 Thread tech coder
we have to traverse in zig zaz or spirally. so we need two stack or two queus. On Mon, Dec 12, 2011 at 12:23 AM, atul anand atul.87fri...@gmail.comwrote: @Gene : if i am not wrong , level order traversal can be done using only 1 queuewhy 2 queue??? On Sun, Dec 11, 2011 at 9:53 PM, AMAN

[algogeeks] Re: A binary tree question

2011-12-11 Thread Gene
One queue certainly suffices. Sometimes two are very nice. E.g. if you have the task of printing all nodes at level N and you don't have level numbers in the nodes. With two queues, all the nodes in a queue at a given time are on the same level, so this problem is elegantly solved. WIth one it's

Re: [algogeeks] A binary tree question

2011-12-11 Thread AMAN AGARWAL
Hi, Yes. Regards, Aman. On Sun, Dec 11, 2011 at 12:54 PM, atul anand atul.87fri...@gmail.comwrote: by zig-zag order means level order traversal ??? On Sun, Dec 11, 2011 at 6:22 AM, AMAN AGARWAL mnnit.a...@gmail.comwrote: Hi, Given a tree, in addition to the left and right pointer, it

[algogeeks] Cliched 'k' largest elements in billion numbers: Heaps or median-of-medians?

2011-12-11 Thread bharath sriram
Hey group, This is kind of a cliched question but given a file with billion numbers and the task is to compute 'k' largest numbers from this file, what approach is preferred? 1) Using heaps 2) Using Median-of-median algorithm. Have read few links which prefer heaps but clearly median of median

Re: [algogeeks] A binary tree question

2011-12-11 Thread atul anand
so algo for zig-zag using two stack would be like this :- let* two stack s1,s2;* toggle = -1; push(root,s1); while ( !isEmpty(s1) || ! isEmpty(s2)) { while( ! isEmtpy(s1)) { print : val=pop(s1); if(toggle == -1) { if(val-right)

Re: [algogeeks] Cliched 'k' largest elements in billion numbers: Heaps or median-of-medians?

2011-12-11 Thread atul anand
Using Median-of-median algorithm is not a practical approch bcozz as you have mentioned it has billion of data. so even if we ignore constant but when we implement is practically then constant matters and value of constant would be very large to make it work for O(n). so heap would me much better

Re: [algogeeks] Cliched 'k' largest elements in billion numbers: Heaps or median-of-medians?

2011-12-11 Thread sumit mahamuni
hey here how will you find the median over the billions of numbers when all data doesnt fit at the same time in memory?? On Mon, Dec 12, 2011 at 6:41 AM, bharath sriram bharath.sri...@gmail.comwrote: Hey group, This is kind of a cliched question but given a file with billion numbers and the

Re: [algogeeks]

2011-12-11 Thread Dheeraj Sharma
yeah..u r rite..i got it On Sun, Dec 11, 2011 at 5:08 PM, Lucifer sourabhd2...@gmail.com wrote: @Dheeraj The ans for 14532 should be 15234.. I am calculating using the above given algo to get to the ans: 1) 4 is the value where A[i] A[i+1] when scanned from the end. 2) The closest