#include<stdio.h>
#include<math.h>
double principal=0,mount=0;
int year=0;
int n=1;
double rate;
void danli(){
printf("请输入的本金：");
scanf("%lf",&principal);
printf("请输入年限：");
scanf("%d",&year);
printf("请输入年利率：");
scanf("%lf",&rate);
mount=principal+principal*rate*year;
printf("本息为：%.2lf\n",mount);
}
void fuli(){
printf("请输入本金：");
scanf("%lf",&principal);
printf("请输入年限：");
scanf("%d",&year);
printf("请输入年利率：");
scanf("%lf",&rate);
printf("请输入年复利次数:");
scanf("%d",&n);
rate=pow((1+rate/n),n)-1;
mount=principal*pow((1+rate),year);
printf("本息为：%.2lf\n",mount);
}
void principaljisuan(){
printf("请输入期望的收益：");
scanf("%lf",&mount);
printf("请输入年限：");
scanf("%d",&year);
printf("请输入年利率：");
scanf("%lf",&rate);
printf("请输入年复利次数:");
scanf("%d",&n);
rate=pow((1+rate/n),n)-1;
principal=mount/pow((1+rate),year);
printf("输出所需本金为：%.2lf\n",principal);
}
main(){
int num=0;
printf("|----------------------------------------------------------|\n");
printf("| 1.复利计算 |\n");
printf("| 2.单利计算 |\n");
printf("| 3.计算本金 |\n");
printf("|----------------------------------------------------------|\n");
printf("请输入选择：");
scanf("%d",&num);
switch(num){
case 1:
fuli();
break;
case 2:
danli();
break;
case 3:
principaljisuan();
default:
return 0;
}
}
