public class Solution {
public double Power(double base, int exponent) {
if(exponent==0 )
return 1;
if(exponent == 1)
return base;
boolean isnegative = false;
if(exponent <0 ){
exponent = -exponent;
isnegative = true;
}
/*double pow = Power(base*base,exponent>>1);
if(exponent%2!=0)
pow = pow*base;
return isnegative ==true?1/pow:pow;*/
//String s = ""+exponent;
String s = Integer.toBinaryString(exponent);
int len =s.length();
double y=1;
//此处,是i从高位到低位吧???
for(int i=len-1;i>=0;i--){
int num = s.charAt(i)-'0';
y=y*y;
if(num==1){
y=y*base;
}
}
return isnegative ==true?1/y:y;
}
}
N的M次方。N是浮点型,M是整数。
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转载自blog.csdn.net/qq_33608638/article/details/80086364
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