Print right view of binary tree

Tags: Algorithm   LeetCode  

Given a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top to bottom.

For example:
Given the following binary tree,

   1            <---
 /   \
2     3         <---
 \     \
  5     4       <---

 

You should return [1, 3, 4].

Credits:
Special thanks to @amrsaqr for adding this problem and creating all test cases.

leon Published by 2015-04-03 22:45

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Number times

Tags: Algorithm  

Single Number I, all twice except one single

Single Number II All numbers occurs triple times except one once

Single Number II All numbers occurs triple times except one twice

Single Number III  all twice numbers, except two single Number

leon Published by 2015-03-02 19:46

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One vs all solutions

Tags: Algorithm  

This kind of question looks this way,

1, need find all possible solutions, we need backtracking method to find them.

2, only need to check if it is available or not, check.

3, only need for a optimist value, Dynamic programming would be very helpful here.

Usually we need dp for optimist solution, backtracking for all solutions, and another idea for avaliable

or statics solution.

 

leon Published by 2015-02-14 14:14

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Tree Traverse

Tags: Algorithm  

Introduction on different version of tree traverse, first is o(n) time,o(n)time, we use a stack,

then try using o(1) space by morris tree. there is also a special method for post traverse 

by using two stacks o(2n).

leon Published by 2015-02-14 01:58

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