50. Pow(x, n)

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

Example 1:

Input: 2.00000, 10Output: 1024.00000

Example 2:

Input: 2.10000, 3Output: 9.26100

Example 3:

Input: 2.00000, -2Output: 0.25000Explanation: 2-2 = 1/22 = 1/4 = 0.25
题意：实现指数函数
代码如下：

/** * @param {number} x * @param {number} n * @return {number} */var myPow = function(x, n) { if(n==0){ return 1; } if(n<0){ n=-n; x=1/x; } return (n%2===0)?myPow(x*x,n/2):x*myPow(x*x,parseInt(n/2));};