class Solution {
public double myPow(double x, int n) {
if (n == 0) return 1;
if (n == -1) return 1/x;
double half = myPow(x,n >> 1);
half *= half;
return ((n & 1) == 1) ? (half * x) : half;
}
}
class Solution {
public double myPow(double x, int n) {
if (n == 0) return 1;
if (n == -1) return 1/x;
double half = myPow(x,n >> 1);
half *= half;
return ((n & 1) == 1) ? (half * x) : half;
}
}