程序：计算1至100间九的个数是多少

#include<stdio.h>
int main()
{
  int m = 0;
  int count = 0;
  for (m = 1; m <100; m++)
  {
    if (m % 10 == 9)
    {
      count++;
    }
    if (m / 90 == 1)
    {
      count++;
    }

  }
  
  printf("九的个数为%d", count);
  
  return 0;
}