Compilare: main.c: In function 'main': main.c:51:9: warning: implicit declaration of function 'exit' [-Wimplicit-function-declaration] 51 | exit(-1); | ^~~~ main.c:2:1: note: include '<stdlib.h>' or provide a declaration of 'exit' 1 | #include <stdio.h> +++ |+#include <stdlib.h> 2 | main.c:51:9: warning: incompatible implicit declaration of built-in function 'exit' [-Wbuiltin-declaration-mismatch] 51 | exit(-1); | ^~~~ main.c:51:9: note: include '<stdlib.h>' or provide a declaration of 'exit' main.c:56:9: warning: incompatible implicit declaration of built-in function 'exit' [-Wbuiltin-declaration-mismatch] 56 | exit(-1); | ^~~~ main.c:56:9: note: include '<stdlib.h>' or provide a declaration of 'exit'