Compilare: user.cpp: In function ‘int main()’: user.cpp:20:39: warning: array subscript has type ‘char’ [-Wchar-subscripts] for(i = 0; i < N; ++i) ++ap[ b[i] ]; ^ user.cpp:26:22: warning: array subscript has type ‘char’ [-Wchar-subscripts] if( ap[ a[i] ] ) --ap[ a[i] ]; ^ user.cpp:26:37: warning: array subscript has type ‘char’ [-Wchar-subscripts] if( ap[ a[i] ] ) --ap[ a[i] ]; ^ user.cpp:32:43: warning: array subscript has type ‘char’ [-Wchar-subscripts] for(i = 0; i < N; ++i) ++ap[ b[i] ]; ^ user.cpp:33:58: warning: array subscript has type ‘char’ [-Wchar-subscripts] for(i = 0; i < K; ++i) res[i] = a[i], --ap[ a[i] ]; ^ user.cpp:44:39: warning: array subscript has type ‘char’ [-Wchar-subscripts] for(i = 0; i < N; ++i) ++ap[ b[i] ]; ^ user.cpp:50:22: warning: array subscript has type ‘char’ [-Wchar-subscripts] if( ap[ a[i] ] ) --ap[ a[i] ]; ^ user.cpp:50:37: warning: array subscript has type ‘char’ [-Wchar-subscripts] if( ap[ a[i] ] ) --ap[ a[i] ]; ^ user.cpp:56:43: warning: array subscript has type ‘char’ [-Wchar-subscripts] for(i = 0; i < N; ++i) ++ap[ b[i] ]; ^ user.cpp:57:58: warning: array subscript has type ‘char’ [-Wchar-subscripts] for(i = 0; i < K; ++i) res[i] = a[i], --ap[ a[i] ]; ^ user.cpp:11:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("vecini2.in","r",stdin); ^ user.cpp:12:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("vecini2.out","w",stdout); ^ user.cpp:16:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&N); ^ user.cpp:17:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",a); ^ user.cpp:18:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",b); ^