Compilare: user.cpp:38:30: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] char line[MAX_LINE] = { NULL }; ^ user.cpp:40:45: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] char characterMatrix[MAX_N][MAX_N] = { NULL }; ^ user.cpp: In function ‘void GetDetails(int, int)’: user.cpp:218:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(fields[id].vecini.size() < k) ^ user.cpp: In function ‘void Read()’: user.cpp:68:40: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d %d", &n, &m, &k); ^ user.cpp:72:36: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%s", &line[0]); ^