Compilare: main.cpp: In function 'void dfs(int)': main.cpp:18:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<v[nod].size();i++){ ~^~~~~~~~~~~~~~ main.cpp:35:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i==v[nod].size() - 1){ ~^~~~~~~~~~~~~~~~~~~ main.cpp:47:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i < v[nod].size() - 1){ ~~^~~~~~~~~~~~~~~~~~~ main.cpp:58:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<v[nod].size();i++){ ~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:71:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("petsoft.in","r",stdin); ^ main.cpp:72:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("petsoft.out","w",stdout); ^