1006 换个格式输出整数

#include <stdio.h>

int main()
{
  int n=0,i=0,b=0;
  int arr[3]={0};
  scanf("%d", &n);
  while (n)//获得n的每一位
  {
    arr[i] = n % 10;
    n /= 10;
    i++;
  }
  while (i!=-1)//保证0也可以
  {
    switch (i)
    {
    case 2:
      while (arr[i])
      {
        printf("B");
        arr[i]--;
      }
      break;
    case 1:
      while (arr[i])
      {
        printf("S");
        arr[i]--;
      }
      break;
    case 0:
      for (b = 1; b <= arr[i]; b++)
        printf("%d", b);
      break;
    }
    i--;
  } 
  return 0;
}