等额本金-c语言俩个整数除法

printf("剩余本金%.2lf ", benjin  - benjin / yue_a * i);

printf("剩余本金%.2lf ", benjin * (1 - 1 / yue_a * i)); /*这不是数学除法*/

#include <stdio.h>
#define M 999
int main()
{
        double benjin = 0.0;
        double lilv = 0.0;
        double nianxian = 0.0;
        double benxi_a = 0.0;
        double lixi_a = 0.0;
        int yue_a = 0;
        int i;
        float yue_benjin = 0.0;
        double lixi[M] = {0.0};
        printf("请输入本金 年利率 年限
");
        scanf("%lf%lf%lf", &benjin, &lilv, &nianxian);
        yue_a = nianxian * 12;
        yue_benjin = benjin /yue_a;
#ifdef DEBUG
        printf("%.2lf
",yue_benjin);
#endif
        for (i = 0; i < yue_a; ++i)
        {
                lixi[i] = (benjin - yue_benjin * i) * lilv /1200;
#ifdef DEBUG
                printf("%.2lf
",lixi[i]);
#endif
                //printf("第%d个月-应还本金%.2lf	-应还利息%.2lf	-剩余本金%.2lf
", i, yue_benjin, lixi[i], benjin * (1 - 1 / yue_a * i));     /*这不是数学 俩个整数除*/
                printf("第%d个月-应还本金%.2lf	-应还利息%.2lf	-剩余本金%.2lf
", i, yue_benjin, lixi[i], benjin  - benjin / yue_a * i);
                lixi_a += lixi[i];
        }
        benxi_a = lixi_a + benjin;
        printf("总本金[%lf] 总利息[%lf] 总本金利息和[%lf]
", benjin, lixi_a, benxi_a);
        return 0;
}