#include "stdio.h"
#include "stdlib.h"
int main()
{
int a = 0, count = 0;
for (a = 0; a <= 100; ++a)
{
if (a < 10 && a == 9)
{
++count;
}
else
{
if (a/10 == 9) ++count;
if (a%10 == 9) ++count;
}
}
printf("1-100内的整数出现了%d次数字9\n",count);
system("pause");
return 0;
}