Compilare: user.cpp: In function ‘void solve1(int)’: user.cpp:55:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < nodes[cnode].size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:64:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ninjago.in", "r", stdin); ^ user.cpp:65:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ninjago.out", "w", stdout); ^