1701 字符串类型
#include<stdio.h>
#include<string.h>
#define max 1000000
int main()
{
char s[max];
scanf("%s",s);
int len= strlen(s);
int i;
int digit=0,letter=0,qita=0;
for(i=0;i<len;i++)
{
if(s[i] >='0' && s[i] <='9')
digit++;
else if(s[i]>='a' && s[i] <='z' || ( s[i] >= 'A' && s[i] <= 'Z'))
letter++;
else
qita++;
}
if(len==digit)
printf("digit\n");
else if(len==letter)
printf("letter\n");
else
printf("mixed\n");
}