A to the power of B

public class Power{
public long power(int a, int b){
        if (b == 0){
            return 1;
        }
        if (a == 0) {
        return 0;    
            }

            long half = power(a,b/2);
        if(b % 2 == 1){
            return half * half * a;
        }
        return half * half;
    }
}