Compilare: user.cpp: In function ‘void solve()’: user.cpp:38:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < G[x].size(); ++i) { ^ user.cpp:65:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < res.size(); ++i) { ^ user.cpp:66:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < G[res[i]].size(); ++j) { ^ user.cpp:75:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < res.size(); ++i) { ^ user.cpp: In function ‘int main()’: user.cpp:81:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sediu.in", "r", stdin); ^ user.cpp:82:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sediu.out", "w", stdout); ^