50. Pow(x, n) (INT; Divide-and-Conquer)
Implement pow(x, n).
思路:二分法,将每次相乘,转化成平方。
class Solution { public: double myPow(double x, int n) { if(n==0) { return 1; } double result = myPow(x, n/2); result*= result; if(n%2==1) result = x * result; else if(n%2==-1) result = (1/x) * result; //negative number return result; } };