iterate7的博客

题目 Given a string which contains only lowercase letters, remove duplicate letters so that every letter appear once and only once. You must make sure your result is the smallest in lexicographical ord

题目 Given a non-empty array of non-negative integers nums, the degree of this array is defined as the maximum frequency of any one of its elements. Your task is to find the smallest possible length o

定义 编辑距离是字符串之间的一种距离度量，也称为Levenshtein距离；这种距离的含义是：通过最少的操作把一个字符串变换成另外一个字符串。 一次操作包括：删除、插入和替换一个字符。 编辑距离越小，代表越相似。 例子 将kitten转换成sitting的步骤： 1. kitten->sitten(替换k->s） 2. sitten->sittin(替换e-&gt...

异或 0和0异或产生0，0和1； 1和0异或得到1；1和1异或得到0。 简单总结：不同的产生1；否则0。代表的是差别。 补充AND，OR。 AND 0&0=0 1&1=1 0&1=0 只有两个同时满足才能满足。 OR 0|0=0 1|1=1 0|1=1 只要有一个满足就满足。 再理解：异或的操作，如同...

题目 In a 2 dimensional array grid, each value grid[i][j] represents the height of a building located there. We are allowed to increase the height of any number of buildings, by any amount (the amounts...

题目 Given an array of words and a width maxWidth, format the text such that each line has exactly maxWidth characters and is fully (left and right) justified. You should pack your words in a greedy a...