面试题53 - II. 0～n-1中缺失的数字

面试题53 - II. 0～n-1中缺失的数字

package main
import "fmt"
func missingNumber1(nums []int) int {
    for i:=1;i<len(nums);i++{
        if nums[i]-nums[i-1]!=1{
            return nums[i-1]+1
        }
    }
    if nums[0]!=0{
        return 0
    }
    return nums[len(nums)-1]+1
}
func missingNumber(nums []int) int {
    left :=0
    right :=len(nums)
    for left<right{
        mid := left+(right-left)>>1
        if nums[mid]==mid{
            left = mid+1
        }else {
            right = mid
        }
    }
    return left
}
func main() {
    fmt.Println(missingNumber([]int{0}))//1
    fmt.Println(missingNumber([]int{1}))//0
    fmt.Println(missingNumber([]int{0,1}))//2
    fmt.Println(missingNumber([]int{0,1,3}))//2
    fmt.Println(missingNumber([]int{0,1,2,3,4,5,6,7,9}))//8
}