LeetCode: Pow(x,n)

Pow(x, n)


Implement pow(x, n).

public class Solution {
    public double pow(double x, int n) {
        // Start typing your Java solution below
        // DO NOT write main() function
        if(n==0) return 1.; 
        if(x==0.) return 0.;
        if(n<0){
            n=-n;
            x=1./x;
        }
        double temp = pow(x,n/2);
        return n%2==0?temp*temp:temp*temp*x;
    }
}

public class Solution {
    public double pow(double x, int n) {
        // Start typing your Java solution below
        // DO NOT write main() function
        if(n==0) return 1.;
        if(x==0) return 0.;
        if(n<0){
            n=-n;
            x=1./x;
        }
        
        double res=1.;
        while(n>0){
            if(n%2 == 1) res*=x;
            x*=x;
            n>>=1;
        }
        return res;
    }
}