复利计算4.0

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
void view()
{
    printf("              |---------------------------------------------|
");
    printf("              |                 单/复利计算                 |
");
    printf("              |---------------------------------------------|
");
    printf("              |1.单利计算                                   |
");
    printf("              |---------------------------------------------|
");
    printf("              |2.复利计算                                   |
");
    printf("              |---------------------------------------------|
");
    printf("              |3.求年限                                     |
");
    printf("              |---------------------------------------------|
");
    printf("              |4.求年利率                                   |
");
    printf("              |---------------------------------------------|
");
    printf("              |5.固定存钱                                   |
");
    printf("              |---------------------------------------------|
");
    printf("              |6.贷款                                       |
");
    printf("              |---------------------------------------------|
");
    printf("              |0.退出系统                                   |
");
    printf("              |---------------------------------------------|
");
}

void danli()
{
    int i,years;      //存钱年数
    double money,r,sum;   //本金,年利率
    printf("请输入本金:");
    scanf("%lf",&money);
    printf("请输入存钱年数:");
    scanf("%d",&years);
    printf("请输入利率:");
    scanf("%lf",&r);
    for(i = 1 ; i<=years; i++)
    {
        sum = r*i*money+money;  
        printf("存入第%d年后的存款总额为:%.2lf


",i,sum);
    }
}

void year()
{
    int i,years,N=100;
    double money,r,sum,A,B,C;
    printf("请输入本金:");
    scanf("%lf",&money);
    printf("请输入目标金钱:");
    scanf("%lf",&sum);
    printf("请输入利率:");
    scanf("%lf",&r);
    C=A=1+r;
    B=sum/money;
    for(i=1;i<N;i++)
    {
       C=C*A;
       if(C>=B)
       {
          break;
       }
    }
    years=i+1;
    printf("所需年数为%d


",years);
}

void nianlilv()
{
    int years;      
    double money,r,sum,B,y;  
    printf("请输入本金:");
    scanf("%lf",&money);
    printf("请输入存钱年数:");
    scanf("%d",&years);
    printf("请输入目标金钱:");
    scanf("%lf",&sum);
    B=sum/money;
    y=1.0/years;
    r=pow(B,y)-1;
    printf("所求年利率为:%-.3lf


",r);
}

void dingtou1()
{
    int years,i;      
    double money,r,Money,v; 
    printf("每月投入本金:");
    scanf("%lf",&money);
    printf("请输入存钱年数:");
    scanf("%d",&years);
    printf("请输入年利率:");
    scanf("%lf",&r);
    money=money*12;
    for(i=1;i<=years;i++)
    {
         v=pow(1+r,i);
    }
    Money=money*(1+r)*(-1+v)/r;
    printf("%d年后本金和利息之和为:%lf


",years,Money);
}

void dingtou2()
{
    int years,i;      
    double money,r,Money,v; 
    printf("每年投入本金:");
    scanf("%lf",&money);
    printf("请输入存钱年数:");
    scanf("%d",&years);
    printf("请输入年利率:");
    scanf("%lf",&r);
    for(i=1;i<=years;i++)
    {
        v=pow(1+r,i);
    }
    Money=money*(1+r)*(-1+v)/r;
    printf("%d年后本金和利息之和为:%lf


",years,Money);
}

void daikuan()
{
    int years,i;      
    double money,r,Money,v; 
    printf("贷款数目:");
    scanf("%lf",&Money);
    printf("还钱期限(年):");
    scanf("%d",&years);
    printf("请输入年利率:");
    scanf("%lf",&r);
    for(i=1;i<=years;i++)
    {
        v=pow(1+r,i);
    }
    money=Money*r/(-1+v)/(1+r);
    money=money/12;
    printf("每月等额本息应还款:%lf


",money);
}

void SUM()
{
    int years,i;      
    double money,r,v,sum;
    printf("请输入本金:");
    scanf("%lf",&money);
    printf("请输入存钱年数:");
    scanf("%d",&years);
    printf("请输入利率:");
    scanf("%lf",&r);
    for(i = 1 ; i<=years; i++)
    {
       v=pow(1+r,i);
       sum = v*money;  
       printf("存入第%d年后的存款总额为:%.2lf
",i,sum); 
    }
}

void benjin()
{
    int years,i;      
    double money,r,v,sum;
    printf("请输入目标金钱:");
    scanf("%lf",&sum);
    printf("请输入存钱年数:");
    scanf("%d",&years);
    printf("请输入利率:");
    scanf("%lf",&r);
    for(i = 1 ; i<=years; i++)
    {
       v=pow(1+r,i);
    }
    money=sum/v;  
    printf("现在必须存入本金为:%.2lf


",money);
}

main()
{
    int n;
    while(1)
    {
la1:view();
        printf("请选择(0-6):");
        scanf("%d",&n);
        switch(n)
        {
    case 1:
        danli();
        break;
    case 2:
        printf("请选择:
");
        printf("1.通过本金求存款总额
");
        printf("2.通过目标总额求本金

");
        scanf("%d",&n);
        switch(n)
        {
        case 1:
           SUM();
            goto la1;
        case 2:
            benjin();
            goto la1;
        }
        case 3:
            year();
            break;
        case 4:
            nianlilv();
            break;
        case 5:printf("1.每月定投
");
               printf("2.每年定投
");
               scanf("%d",&n);
            switch(n)
            {
            case 1:
            dingtou1();
            goto la1;
            case 2:
                dingtou2();
                goto la1;
            }
            case 6:
                daikuan();
                break;

    case 0:
        n=0;exit(0);
    }
    }
}

这个程序主要增加了贷款这个功能，并且设置了循环的功能，使得程序能根据使用者意愿执行所需的功能，不会自动退出。