Compilare: user.cpp: In function ‘int main()’: user.cpp:85:47: warning: array subscript has type ‘char’ [-Wchar-subscripts] mat[i][j] = code_to_char[mat[i][j]]; ^ user.cpp:126:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] while ( bg < ed && ( mat[t.i][t.j] != 'G' || t.d <= 1 ) ) { ^ user.cpp:126:38: warning: array subscript has type ‘char’ [-Wchar-subscripts] while ( bg < ed && ( mat[t.i][t.j] != 'G' || t.d <= 1 ) ) { ^ user.cpp:127:16: warning: array subscript has type ‘char’ [-Wchar-subscripts] mat[t.i][t.j] = 'R'; ^ user.cpp:127:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] mat[t.i][t.j] = 'R'; ^ user.cpp:75:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d%d ", &n, &m ); ^ user.cpp:81:43: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread( mat[i] + 1, 1, m + 1, fin ); ^