69. x 的平方根

69. x 的平方根

package main
import "fmt"
func mySqrt(x int) int {
    if x==0 ||x==1{
        return x
    }
    left :=0
    right :=x
    for left<=right{
        mid := (left+right)>>1
        r := mid*mid
        if r==x {
            return mid
        }else if r>x  {
            right =mid-1
        }else {
            left = mid+1
        }
    }
    return left-1
}
func main() {
    fmt.Println(mySqrt(4))
    fmt.Println(mySqrt(6))
    fmt.Println(mySqrt(8))
    fmt.Println(mySqrt(10))
}