Eroare de compilare: user.cpp: In function ‘int pair_up(int)’: user.cpp:16: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:42: error: ‘memset’ was not declared in this scope user.cpp:27: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result