Compilare: user.cpp: In function ‘void solve()’: user.cpp:27: warning: comparison between signed and unsigned integer expressions user.cpp:18: warning: unused variable ‘j’ user.cpp:18: warning: unused variable ‘k’ user.cpp: In function ‘int main()’: user.cpp:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result