Compilare: main.c: In function 'main': main.c:31:13: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[505]' [-Wformat=] 31 | scanf("%s %s",&s1,&s2); | ~^ ~~~ | | | | | char (*)[505] | char * main.c:31:16: warning: format '%s' expects argument of type 'char *', but argument 3 has type 'char (*)[505]' [-Wformat=] 31 | scanf("%s %s",&s1,&s2); | ~^ ~~~ | | | | char * char (*)[505] main.c:32:7: warning: implicit declaration of function 'strlen' [-Wimplicit-function-declaration] 32 | N=strlen(s1); | ^~~~~~ main.c:2:1: note: include '<string.h>' or provide a declaration of 'strlen' 1 | #include <stdio.h> +++ |+#include <string.h> 2 | main.c:32:7: warning: incompatible implicit declaration of built-in function 'strlen' [-Wbuiltin-declaration-mismatch] 32 | N=strlen(s1); | ^~~~~~ main.c:32:7: note: include '<string.h>' or provide a declaration of 'strlen'