等额本息

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
//ACPI  等额本息 Average Capital Plus Interest
float fLoanSum;//总需要贷款金额
float fMonthIRate;//月利率（年利率求得）
float fACPI_MonthPay;//ACPI月付
float fACPI_PaidI = 0;//ACPI已经付清的金额
float fACPI_Sum = 0;//ACPI贷款还款的本息和
int iMonth, i;

int main()
{    FILE *FileStream;
    float fMonthI, fMonthP;//月息和本金

    FileStream = fopen("LoanSaved.txt", "w+");

    puts("请输入：\n贷款总额(元)\t贷款年限\t贷款利率%：");
    scanf("%f %d %f", &fLoanSum, &iMonth, &fMonthIRate);
    fMonthIRate /= 12;//求得月利率
    fMonthIRate /= 100;//去掉%，直接算得月利率：x%的值
    iMonth *= 12;

    //等额本息
    fACPI_MonthPay = fLoanSum*fMonthIRate*pow(1 + fMonthIRate, iMonth) / (pow(1 + fMonthIRate, iMonth) - 1); //每月本息和
    fputs("ACPI:\n", FileStream);
    for (i = 1; i <= iMonth; i++)
    {
        fMonthI = (fLoanSum - fACPI_PaidI)*fMonthIRate; //每月利息
        fACPI_Sum += fMonthI;                           //纳入还款总额

        fMonthP = fACPI_MonthPay - fMonthI;             //每月本金
        fACPI_PaidI += fMonthP;                         //已付本金

        fprintf(FileStream, "   Month[%d]:Sum:%.2f  MonthInterest:%.2f  MonthPrincipal:%.2f\n", i, fMonthI + fMonthP, fMonthI, fMonthP);
    }
    return 0;
}