Missing Number
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
.
Note:
Your algorithm should run in linear runtime complexity. Could you implement it using only constant extra space complexity?
Credits:
Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.
等差数列求和,易得缺失值。
class Solution {
public:
int missingNumber(vector<int>& nums) {
int n = nums.size();
int expect = (n+) * n / ;
for(int i = ; i < n; i ++)
expect -= nums[i];
return expect;
}
};