计算字符串中的数字，大小，写字母个数
#include <stdio.h>
#include <ctype.h>
#pragma warning (disable:4996)
void fun(int cd, int cu, int cs )
{ char c;
printf("用回车键结束输入！\n");
while ((c=getchar()) != '\n')
{
if (c>='0' && c<='9') ++cd;
if (c>='A'&& c<='Z') ++cu;
if (c>='a' && c<='z') ++cs;
}
}
main( )
{ int cd, cu, cs;
cd = cu = cs = 0;
fun( &cd, &cu, &cs );
printf("数字的个数: %d\n", cd);
printf("大写字母的个数: %d\n", cu);
printf("小写字母的个数: %d\n", cs);
}