LeetCode 50: Pow(x, n)

LeetCode Math

Implement pow(x, n).

代码

double myPow(double x, int n) {
    double res = 1;
    double flag = x;
    int m = n;
	if (n < 0) {
		x = 1 / x;
		if (n == INT_MIN) {
			n = INT_MAX;
		} else {
			n = -n;
		}
	}
	while (n>0) {
		if (n & 1 == 1) {
			res = res*x;
		}
		x *= x;
		n = n >> 1;
	}
	if (m == INT_MIN) {
	    if (flag < 0) {
	        return -res;
	    }
	}
    return res;
}