268. Missing Number LeetCode
2016-02-13 17:58
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题意:给出一个数组,有n个数,是0到n的序列,少了其中的某个数,求这个缺少的数。
题解:异或,把数组和1到n异或一遍,异或之和就是答案。因为相当于所有的数字都出现了2次,没出现那个数只出现了一次。
题解:异或,把数组和1到n异或一遍,异或之和就是答案。因为相当于所有的数字都出现了2次,没出现那个数只出现了一次。
class Solution { public: int missingNumber(vector<int>& nums) { int ans = 0; int n = nums.size(); for(int i = 1; i <= n; i++) ans ^= (i ^ nums[i - 1]); return ans; } };
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