nx.cpp: In function 'void Solve()': nx.cpp:103: warning: comparison between signed and unsigned integer expressions nx.cpp:103: warning: comparison between signed and unsigned integer expressions nx.cpp: In function 'int main()': nx.cpp:157: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result nx.cpp:158: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result