C-(练习)Sn = a+aa+aaa+aaaa+aaaaa的前5项之和

#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<string.h>
//求Sn = a+aa+aaa+aaaa+aaaaa的前5项之和，其中a是一个数字
//例如：2+22+222+2222+22222
int main()
{
    int a = 0;
    int n = 0;
    scanf("%d %d", &a,&n);

    int i = 0;
    int sum = 0;
    int ret = 0;
    for (i = 0; i < n; i++)
    {
        ret = ret * 10 + a;
        sum = sum + ret;
    }
    printf("sum=%d\n", sum);
    return 0;
}