Pow(x, n)

Implement pow(x, n), which calculates x raised to the power n (i.e. xn).

Example 1:

Input: x = 2.00000, n = 10 Output: 1024.00000

Example 2:

Input: x = 2.10000, n = 3 Output: 9.26100

Example 3:

Input: x = 2.00000, n = -2 Output: 0.25000 Explanation: 2-2 = 1/22 = 1/4 = 0.25

Constraints: -100.0 < x < 100.0 -231 <= n <= 231-1 -104 <= xn <= 104

Solution:

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class Solution {
    public double myPow(double x, int n) {
        if (n==0) {
            return 1.0;
        }

        double half = myPow(x, n/2);

        if (n%2==0){
            return half*half;
        } else if (n>0) {
            return half*half*x;
        } else {
            return half*half* (1/x);
        }
    }
}