Compilare: user.c: In function ‘main’: user.c:23:9: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘char (*)[105]’ [-Wformat=] scanf( "%s\n" , &s ); ^ user.c:24:9: warning: implicit declaration of function ‘strlen’ [-Wimplicit-function-declaration] l = strlen(s); ^ user.c:24:13: warning: incompatible implicit declaration of built-in function ‘strlen’ [enabled by default] l = strlen(s); ^ user.c:10:18: warning: unused variable ‘ch’ [-Wunused-variable] char s[105], ch; ^ user.c:6:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen( "cifra.in" , "r" , stdin ); ^ user.c:7:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("cifra.out","w",stdout); ^ user.c:21:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf( "%d" , &t ); ^ user.c:23:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf( "%s\n" , &s ); ^