leetcode3/Pow(x, n).java at master · 1code/leetcode3 · GitHub

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Implement pow(x, n)

public class Solution {
    public double pow(double x, int n) {
        if (n == 0) return 1;
        else if (n % 2 == 0) {
            double d = pow(x, n / 2);
            return d * d;
        } else if (n > 0) {
            double d = pow(x, (n - 1) / 2);
            return d * d * x;
        } else {
            double d = pow(x, (n + 1) / 2);
            return d * d / x;
        }
    }
}