Compilare: user.cpp: In function ‘void writeData()’: user.cpp:90:10: warning: unused variable ‘n’ [-Wunused-variable] int n = sol.size(); ^ user.cpp: In function ‘void readData()’: user.cpp:75:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(FIN, "r", stdin); ^ user.cpp:77:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s %s", A + 1, B + 1); ^ user.cpp: In function ‘void writeData()’: user.cpp:88:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(FOUT, "w", stdout); ^