Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:281:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < graph[x].size(); ++i) ^ user.cpp: In function ‘void solve()’: user.cpp:301:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < qrys.size(); ++i){ ^ user.cpp:302:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(p < edges.size() && edges[p].spd < qrys[i].spd){ ^ /tmp/ccJZizo6.o: In function `read()': user.cpp:(.text+0x33d6): warning: the `gets' function is dangerous and should not be used.