题目描述
给定一个double类型的浮点数base和int类型的整数exponent。求base的exponent次方。
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class Solution { public: double Power(double base, int exponent) { int p = abs(exponent); if(p==0) return 1; if(p==1) return base; double result=1; result=Power(base,p>>1);//相当于exponent%2 result=result*result; if(p&1==1)//相当于%2判断是否为奇数 result*=base; if(exponent<0) return 1.0/result; else return result; } };