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:
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);
}
}
}