#include <stdio.h>
int
main(int argc, char *argv[])
{
char str[101]={0};
char *p=str;
int digitCount=0;
int letterCount=0;
printf("please input a string: ");
gets(str);
printf("your input string is: %s\n",str);
while(*p!='\0')
{
if(*p>'0'&&*p<'9')
{
digitCount++;
}
else if((*p>'a'&&*p<'z')||(*p>'A'&&*p<'Z'))
{
letterCount++;
}
p++;
}
if(digitCount==0&&letterCount==0)
{
printf("you have nothing input.\n");
}
else if(digitCount>0&&letterCount>0)
{
printf("mixed\n");
}
else if(digitCount>0&&letterCount==0)
{
printf("digit\n");
}
else if(digitCount==0&&letterCount>=0)
{
printf("letter\n");
}
else
{
//no way
}
getchar();
return 0;
}