例如：2+22+222+2222+22222

#include<stdio.h>
int main()
{
    int a, n;
    int i, sum = 0,tmp=0;
    printf("请输入需要的个数和数值:\n");
    scanf("%d%d",&n,&a);
    for (i = 0; i < n; i++)
    {
        tmp = tmp * 10 + a;
        sum = sum + tmp;
    }
    printf("%d\n",sum);
    return 0;
}