Compilare: user.c: In function ‘main’: user.c:55:5: warning: implicit declaration of function ‘malloc’ [-Wimplicit-function-declaration] interv *intv = malloc(n * sizeof(interv)); ^ user.c:55:20: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] interv *intv = malloc(n * sizeof(interv)); ^ user.c: In function ‘swap’: user.c:12:1: warning: control reaches end of non-void function [-Wreturn-type] } ^