Compilare: main.cpp: In function 'void sift_down(int, std::vector<int>&, const std::vector<int>&, std::vector<int>&)': main.cpp:43:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(left_son(current) < heap.size() && distances[heap[left_son(current)]] < distances[heap[current]]){ ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~ main.cpp:46:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(right_son(current) < heap.size() && distances[heap[right_son(current)]] < distances[heap[current]] && distances[heap[right_son(current)]] < distances[heap[left_son(current)]]){ ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~ main.cpp: In function 'std::vector<int> dijkstra(const std::vector<std::vector<std::pair<int, int> > >&, int)': main.cpp:62:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < graph.size(); ++i){ ~~^~~~~~~~~~~~~~ main.cpp:78:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < graph[current_node].size(); ++i){ ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:111:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < result.size(); ++i){ ~~^~~~~~~~~~~~~~~