求a+aa+aaa+aaaa+aaaaa的值

2                               k=0*10+2=2
2*10 + 2 = 22                   k=2*10+2=22
22*10 + 2 = 222                 k=22*10+2=222
222*10 + 2 = 2222               k=222*10+2=2222

int k = 0;//用于计算 a,aa,aaa,aaaa,aaaaa
int i = 0;
for (i = 0; i < n; i++)
  {
  k = k * 10 + a;
  }

#include<stdio.h>
int main()
{
  int a = 0;
  int n = 0;
  scanf("%d%d", &a, &n);
  int k = 0;//用于计算 a,aa,aaa,aaaa,aaaaa
  int i = 0;
  int sum = 0;
  for (i = 0; i < n; i++)
  {
  k = k * 10 + a;
  sum += k;
  }
  printf("%d\n", sum);
  return 0;
}