Compilare: user.c: In function ‘main’: user.c:91:13: warning: array subscript has type ‘char’ [-Wchar-subscripts] fprintf(out, "%d %d %d %d %d %d\n", a[sum[i].ind1], ^ user.c:92:49: warning: array subscript has type ‘char’ [-Wchar-subscripts] a[sum[i].ind2], ^ user.c:93:49: warning: array subscript has type ‘char’ [-Wchar-subscripts] a[sum[i].ind3], ^ user.c:94:49: warning: array subscript has type ‘char’ [-Wchar-subscripts] a[sum[j].ind1], ^ user.c:95:49: warning: array subscript has type ‘char’ [-Wchar-subscripts] a[sum[j].ind2], ^ user.c:96:49: warning: array subscript has type ‘char’ [-Wchar-subscripts] a[sum[j].ind3]); ^ user.c:52:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d %d\n", &N, &S); ^ user.c:56:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &a[i]); ^