Compilare: user.c:15:49: warning: data definition has no type or storage class int M,N,A[Nmax],B[Nmax],D[Nmax][Nmax],sir[Nmax];bst; ^~~ user.c:15:49: warning: type defaults to ‘int’ in declaration of ‘bst’ [-Wimplicit-int] user.c: In function ‘main’: user.c:19:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("cmlsc.in", "r", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:20:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("cmlsc.out", "w", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:21:5: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d,%d",&M,&N); ^~~~~~~~~~~~~~~~~~~~ user.c:23:9: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&A[i]); ^~~~~~~~~~~~~~~~~ user.c:25:9: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&B[i]); ^~~~~~~~~~~~~~~~~ user.c:28:23: warning: ‘j’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(A[i]==B[j]){ ~^~~