利息的后续要求

#include<stdio.h>
#include<math.h>
#define x1
#define x2
double danli(double i,int N,double P)//单利计算
{
double nlx,F;
nlx = P*i;
F = nlx*N + P;
return F;

}

double fuli(double i,int W,int N,double P)//复利计算
{
double F;
i=pow(1+i/W,W)-1;
F=P*pow((i+1),N);
return F;
}

double gusuan(double i,int W,int N,double F)//估算
{
double P;
i = pow(1+i/W,W)-1;
P = F/pow((i+1),N);
return P;
}
double shijian(double P,double i,double F)//时间
{
double N,x;
x=F/P;
N=(log(x))/(log(i+1));
return N;

}
double nianxian(double P,double N,double F)//年限
{
double i;
i = pow(F/P,1.0/N)-1.0;
return i;
}
double sum()
{
double y,yue,F=0.0,i,mi;
double nl,yl;
int N;
int ch,j;
printf("****** 1-年投资  2-月投资 ******\n");
scanf("%d",&ch);
if(ch == 1)
{
printf("请输入年投资额：\n");
scanf("%lf",&y)  x2;
}
else
{
printf("请输入月投资额：\n");
scanf("%lf",&yue)  x2;
}

printf("请输入年利率\n");
scanf("%lf",&i)  x2;
printf("请输入年限\n");
scanf("%d",&N)  x2;

if(ch == 1)
{
F = y;
for(j=0 ; j<N ; j++)
{
nl = F*i;
F=y+nl+F;
}
return F-y;
}
else
{
F = yue;
mi = i/12.0;
for(j=0 ; j<N*12 ; j++)
{
yl = F*mi;
F=yue+yl+F;
}
return F-yue;
}

}
double refund()
{
double P,i,month_amount;
int N,month;
printf("************您进入本息还款计算************\n");
printf("请输入贷款金额：\n");
scanf("%lf",&P);
printf("请输入年利率：\n");
scanf("%lf",&i);
printf("请输入归还年限：\n");
scanf("%d",&N);

//每月还款额=[贷款本金×月利率×（1+月利率）^还款月数]÷[（1+月利率）^还款月数－1]

i = i/12;
month = N*12;
month_amount = P*i*pow((1.0+i),month)/(pow(1.0+i,month)-1);
return month_amount;

}
void main()
{
double P,F1,F,i; //P是本金，F是收益，i年利率
int N,W,ch2; //是期限
while(1)
{
printf("\t\t***************欢迎使用复利计算器*************\n\n");
printf("\t\t|     -----1:复利----------------    |\n\n");
printf("\t\t|     -----2:单利----------------    |\n\n");
printf("\t\t|     ------3:估算----------------    |\n\n");
printf("\t\t|     -------4:年限----------------    |\n\n");
printf("\t\t|     ------5:年利率--------------    |\n\n");
printf("\t\t|     ------6:月年收益------------    |\n\n");
printf("\t\t|     ------7:等额本息还款--------    |\n\n");
printf("\t\t|     ------0:为退出----------------  |\n\n");
printf("\t\t**************请选择想要的功能************\n");
x1  scanf("%d",&ch2)  x2;//控制选择
switch(ch2){
case 1:
printf("请输入本金：\n");
scanf("%lf",&P);
printf("请输入年利率\n");
scanf("%lf",&i);
printf("请输入年限：\n");
scanf("%d",&N);
printf("请输入复利次数：\n");
scanf("%d",&W);
F1 = fuli(i,W,N,P); break;
case 2:
printf("请输入本金：\n");
scanf("%lf",&P);
printf("请输入年利率\n");
scanf("%lf",&i);
printf("请输入年限：\n");
scanf("%d",&N);
F1 = danli(i,N,P); break;
case 3:
printf("请输入本利\n");
scanf("%lf",&F);
printf("请输入年利率\n");
scanf("%lf",&i);
printf("请输入年限：\n");
scanf("%d",&N);
printf("请输入复利次数：\n");
scanf("%d",&W);
F1 = gusuan(i,W,N,F);
break;

case 4:
printf("请输入本金\n");
scanf("%lf",&P);
printf("请输入年利率\n");
scanf("%lf",&i);
printf("请输入本利\n");
scanf("%lf",&F);
F1=shijian(P,i,F);
break;
case 5:

printf("请输入本金：\n");
scanf("%lf",&P);
printf("请输入本利：\n");
scanf("%lf",&F);
printf("请输入年限\n");
scanf("%d",&N);
F1=nianxian(P,N,F);

break;
case 6:
F1=sum();
break;
case 7:
F1=refund();
break;
case 0:break;
default:
printf("输入不合法！！\n");
continue ;
}
if(ch2==0)
break;
printf("结果为：%.2lf\n",F1);
}
}