Compilare: user.c: In function ‘main’: user.c:32:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(nrAparitii[sir2[i]] == 0){ ^ user.c:33:25: warning: array subscript has type ‘char’ [-Wchar-subscripts] nrAparitii[sir2[i]] = 1; ^ user.c:58:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] nrAparitii[sir1[i]]++; ^ user.c:9:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("playwithstrings.in","r",stdin); ^ user.c:10:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("playwithstrings.out","w",stdout); ^ user.c:15:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.c:18:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%s", &task, sir1); ^ user.c:21:18: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s", sir2); ^