Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array.
For example,
Given nums = [0, 1, 3] return 2.
121/145
思路：bit manipulation A^A=0 A^0=A.
nums[i]属于0- i+1，他们中必有一个数是missing的，所以跟i+1异或之后肯定会留下最后0^A=A
public class Solution { public int missingNumber(int[] nums) { int len=nums.length; for(int i=0;i<nums.length;i++){ len^=i; len^=nums[i]; } return len; } }
原文：http://www.cnblogs.com/Machelsky/p/5945331.html