Compilare: main.cpp: In function 'void dfsmx(long long int, long long int, long long int)': main.cpp:24:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<adj1[cr].size();i++){ ~^~~~~~~~~~~~~~~~ main.cpp: In function 'std::pair<long long int, long long int> dfs1(long long int, long long int)': main.cpp:40:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<adj1[cr].size();i++){ ~^~~~~~~~~~~~~~~~ main.cpp:50:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<vps.size();i++){ ~^~~~~~~~~~~ main.cpp: In function 'void dfs2(long long int, long long int, long long int)': main.cpp:66:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<adj1[cr].size();i++){ ~^~~~~~~~~~~~~~~~ main.cpp: In function 'int32_t main()': main.cpp:76:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arb2.in","r",stdin); ^ main.cpp:77:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arb2.out","w",stdout);/***/ ^