Implement pow(x, n), which calculates x raised to the power n (xn).
Example 1:
Input: 2.00000, 10
Output: 1024.00000
Example 2:
Input: 2.10000, 3
Output: 9.26100
Example 3:
Input: 2.00000, -2
Output: 0.25000
Explanation: 2-2 = 1/22 = 1/4 = 0.25
Note:
-100.0 < x < 100.0
n is a 32-bit signed integer, within the range [−231, 231 − 1]
class Solution {
public double myPow(double x, int n) {
double result=1.0;
for(int i=n;i!=0;i/=2) {
if(i%2!=0)result*=x;
x*=x;
}
return n<0?1/result:result;
}
}