[LeetCode] Sort Colors (Java)

Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue. Here, we will use the integers 0, 1, and 2 to represent the color red, white, and blue respectively. Follow up: A rather straight forward … Read more

[LeetCode] Longest Valid Parentheses

Got stuck in this problem for one hour. I was trying to use a variable left to count the left parentheses. However, we should not only count the number of them, but also the position of them. Then we need to use stack. There is a very elegant solution here (In Java): http://rleetcode.blogspot.com/2014/01/longest-valid-parentheses.html This problem really cost … Read more