weidagang’s gists

weidagang / functional_stack.js

Created July 28, 2013 07:09

Functional stack

weidagang / minimum-window-substring.cpp

Last active December 25, 2015 00:19

Mininum Window Substring http://oj.leetcode.com/problems/minimum-window-substring/

	/*
	Given a string S and a string T, find the minimum window in S which will contain all the characters in T in complexity O(n).

	For example,
	S = "ADOBECODEBANC"
	T = "ABC"
	Minimum window is "BANC".

	Note:
	If there is no such window in S that covers all characters in T, return the emtpy string "".

weidagang / two-sum.cpp

Last active December 25, 2015 00:19

Two Sum http://oj.leetcode.com/problems/two-sum/

	/*
	Given an array of integers, find two numbers such that they add up to a specific target number.

	The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2. Please note that your returned answers (both index1 and index2) are not zero-based.

	You may assume that each input would have exactly one solution.

	Input: numbers={2, 7, 11, 15}, target=9
	Output: index1=1, index2=2
	*/

weidagang / state-monad.coffee

Created October 10, 2013 03:09

State Monad in CoffeeScript from https://gist.github.com/igstan/936519

	push = (element) -> (stack) ->
	newStack = [element].concat stack
	{value: element, stack: newStack}

	pop = (stack) ->
	element = stack[0]
	newStack = stack.slice 1
	{value: element, stack: newStack}

	bind = (stackOperation, continuation) -> (stack) ->

weidagang / LCS.java

Last active January 1, 2016 18:09

Longest Common Substring

	public class LCS {

	public static void main(String... args) throws Exception {
	System.out.println(lcs("Milexxs", "xxxxxxxM"));
	}

	public static String lcs(String a, String b) {
	if (null == a \|\| null == b) return "";
	String longest = "";
	for (int i = 0; i < a.length(); ++i) {

weidagang / trapping-rain-water.cpp

Last active August 29, 2015 13:56

Trapping Rain Water http://oj.leetcode.com/problems/trapping-rain-water/

	/*
	http://oj.leetcode.com/problems/trapping-rain-water/

	Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it is able to trap after raining.

	For example,
	Given [0,1,0,2,1,0,1,3,2,1,2,1], return 6.

	The above elevation map is represented by array [0,1,0,2,1,0,1,3,2,1,2,1]. In this case, 6 units of rain water (blue section) are being trapped. Thanks Marcos for contributing this image!
	*/

weidagang / binary-tree-level-order-traversal-2.cpp

Last active August 29, 2015 13:56

Binary Tree Level Order Traversal II http://oj.leetcode.com/problems/binary-tree-level-order-traversal-ii/

	/*
	http://oj.leetcode.com/problems/binary-tree-level-order-traversal-ii/

	Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to right, level by level from leaf to root).

	For example:
	Given binary tree {3,9,20,#,#,15,7},

	return its bottom-up level order traversal as:

weidagang / interleaving-string.cpp

Created February 8, 2014 13:11

Interleaving String http://oj.leetcode.com/problems/interleaving-string/

	/*
	http://oj.leetcode.com/problems/interleaving-string/

	Given s1, s2, s3, find whether s3 is formed by the interleaving of s1 and s2.

	For example,
	Given:
	s1 = "aabcc",
	s2 = "dbbca",

weidagang / kth-smallest-in-binary-search-tree.cpp

Last active August 29, 2015 13:56

Kth Smallest Number in Binary Search Tree

	/*
	Find the kth smallest number in the binary search tree.
	*/

	#include <cstdio>
	#include <stack>
	#include <queue>

	struct TreeNode {
	int val;

weidagang / binary-tree-inorder-traversal.cpp

Created February 10, 2014 08:49

binary-tree-inorder-traversal http://oj.leetcode.com/problems/binary-tree-inorder-traversal/

	/*
	Given a binary tree, return the inorder traversal of its nodes' values.

	For example:
	Given binary tree {1,#,2,3},
	1
	\
	2
	/
	3

Dagang Wei weidagang