Compilare: user.cpp: In function ‘void solve(int)’: user.cpp:38: warning: comparison between signed and unsigned integer expressions user.cpp:43: warning: comparison between signed and unsigned integer expressions user.cpp:57: warning: comparison between signed and unsigned integer expressions user.cpp:87: warning: comparison between signed and unsigned integer expressions user.cpp:30: warning: unused variable ‘a1’ user.cpp:30: warning: unused variable ‘a2’ user.cpp:30: warning: unused variable ‘a3’ user.cpp: In function ‘int main()’: user.cpp:167: warning: comparison between signed and unsigned integer expressions user.cpp:145: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:146: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:148: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:152: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result