#include <stdio.h>
#include<ctype.h>
int main() {
char s[105];
while(~scanf("%s",s))
printf("%c",toupper(s[0]));
return 0;
}
toupper()将字母转换为大写

#include <stdio.h>
#include<ctype.h>
int main() {
char s[105];
while(~scanf("%s",s))
printf("%c",toupper(s[0]));
return 0;
}
toupper()将字母转换为大写