1 class Solution { 2 public: 3     double findval(double x,int n) 4     { 5         if(n==0) return 1; 6         if(n==1) return x; 7         double value = http://www.mamicode.com/pow(x,n/2); 8         if(n%2) return value*value*x; 9         else return value*value;10     }11     double pow(double x, int n) {12         bool flag = false;13         if(n<0)14         {15             n=-n;16             flag = true;17         }18         double value =http://www.mamicode.com/ findval(x,n);19         if(flag) return 1/value;20         else return value;21         22     }23 };