Java | Leetcode Java题解之第268题丢失的数字

题目：

题解：

class Solution {public int missingNumber(int[] nums) {int n = nums.length;int total = n * (n + 1) / 2;int arrSum = 0;for (int i = 0; i < n; i++) {arrSum += nums[i];}return total - arrSum;}
}