>>280
#include <stdio.h>
#include <string.h>
int main(){
FILE *fp;
char s1[0xff], s2[0xff];
fp = fopen("in.txt", "r");
fgets(s1, sizeof(s1), fp);
while(fgets(s2, sizeof(s2), fp) != NULL){
if(strcmp(s1, s2) != 0)printf("%s", s1);
strcpy(s1, s2);
}
printf("%s\n", s1);
return 0;
}

>>276
おいおい、voidで値返すなよ