Compilare: user.cpp: In function ‘void dfs(int, int, int)’: user.cpp:43:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < l[x].size(); ++i) ~~^~~~~~~~~~~~~ user.cpp: In function ‘int lca(int, int)’: user.cpp:85:13: warning: unused variable ‘lvl’ [-Wunused-variable] int diffh, lvl = 0; ^~~ user.cpp: In function ‘int solve(int, int, int)’: user.cpp:119:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(indspeeds < speeds.size() && speeds[indspeeds].first <= k) ~~~~~~~~~~^~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:159:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < q.size(); ++i) ~~^~~~~~~~~~