Compilare: main.cpp: In member function 'int element::get_best_node()': main.cpp:22:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<nodes.size(); i++) ~^~~~~~~~~~~~~ main.cpp: In function 'void dfs(int, std::vector<int>&)': main.cpp:74:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<graph[node_here].size(); i++) ~^~~~~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'void solve()': main.cpp:121:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<results.size(); i++) ~^~~~~~~~~~~~~~~ main.cpp: In function 'element merge_two_elements(element&, element&)': main.cpp:40:61: warning: 'result' may be used uninitialized in this function [-Wmaybe-uninitialized] results.push_back({a.get_best_node()+1,b.get_best_node()+1}); ~~~~~~~~~~~~~~~~~^~ main.cpp:40:41: warning: 'result' may be used uninitialized in this function [-Wmaybe-uninitialized] results.push_back({a.get_best_node()+1,b.get_best_node()+1}); ~~~~~~~~~~~~~~~~~^~