/**
* @param {number[]} nums
* @return {number}
*/
var missingNumber = function(nums) {
const expectSum = nums.length * (nums.length + 1) / 2 //原本的和
let min = nums[0], max = nums[0], sum = 0
for (let i in nums) {
sum += nums[i]
}
return expectSum - sum
};
2021.10.6
class Solution:
def missingNumber(self, nums: List[int]) -> int:
n=0
s=0
for num in nums:
n+=1
s+=num
return n*(n+1)//2-s
