leetcode/100-n/268. 丢失的数字.md
https://leetcode-cn.com/problems/missing-number/
func missingNumber(nums []int) int {
n := len(nums)
sum := 0
for _, item := range nums {
sum += item
}
return (1 + n) * n / 2 - sum
}
https://leetcode-cn.com/problems/missing-number/
func missingNumber(nums []int) int {
n := len(nums)
sum := 0
for _, item := range nums {
sum += item
}
return (1 + n) * n / 2 - sum
}