Compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:33:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<g[n].size();i++) ~^~~~~~~~~~~~ user.cpp: In function ‘void solve(int)’: user.cpp:66:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<g[TRACK].size();i++) ~^~~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:87:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<g[X].size();i++) ~^~~~~~~~~~~~