数值的整数次方

class Solution {
public:
    double Power(double base, int exponent) {
    	double mul=1.0;
		 /* 如果exponent = 0 输出1 */
	        if(exponent == 0)
	        {
	            return 1.00000;
	        }

	        /* 如果base = 0 输出0 */
	        if(base >= -0.000001 && base <= 0.000001)
	        {
	            return 0;
	        }
	        /* 如果指数大于0 */
	        if(exponent > 0)
	        {
	            for(int index = 0; index < exponent; index++)
	            {
	                mul *= base;
	            }
	        }
	        else
	        {
	            exponent = -exponent;
	            for(int index = 0; index < exponent; index++)
	            {
	                mul *= base;
	            }
	            mul = 1.0/mul;
	        }


	        return mul;
    }
};