#include<stdio.h>
int main()
{
	double x;
	scanf("%lf",&x);
	if(x<=1600)
		printf("%.2lf\n",x*0);
	else if(x<=2500)
		printf("%.2lf\n",(x-1600)*0.05);
	else if(x<=3500)
		printf("%.2lf\n",(x-1600)*0.1);
	else if(x<=4500)
		printf("%.2lf\n",(x-1600)*0.15);
	else
		printf("%.2lf\n",(x-1600)*0.2);
	return 0;
}
原文:http://www.cnblogs.com/Evence/p/4290738.html