Compilare: user.cpp: In function ‘void scan()’: user.cpp:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘bool pairup(int)’: user.cpp:26: warning: comparison between signed and unsigned integer expressions user.cpp:32: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void suport(int)’: user.cpp:54: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:91: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:92: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result