lintcode-medium-Pow(x, n)

Implement pow(x, n).

Notice

You don't need to care about the precision of your answer, it's acceptable if the expected answer and your answer 's difference is smaller than

1e-3

.

Example

Pow(2.1, 3) = 9.261
Pow(0, 1) = 0
Pow(1, 0) = 1

Challenge

O(logn) time

public class Solution {
/**
* @param x the base number
* @param n the power number
* @return the result
*/
public double myPow(double x, int n) {
// Write your code here

if(n == 0)
return 1;
if(n == 1)
return x;

if(n > 1){
if(n % 2 == 0){
double temp = myPow(x, n / 2);
return temp * temp;
}
else{
return myPow(x, n - 1) * x;
}
}
else{
return 1 / myPow(x, -n);
}
}
}