Compilare: user.cpp:18:34: warning: converting to non-pointer type ‘int’ from NULL [-Wconversion-null] int cells[MAX_N][MAX_N] = { NULL }; ^ user.cpp: In function ‘void Read()’: user.cpp:45:33: 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:49:37: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d", &y, &x); ^ user.cpp:57:51: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d %d %d", &y1, &x1, &y2, &x2); ^