Compilare: main.cpp: In function 'int main()': main.cpp:33:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<a.size(); i++) ~^~~~~~~~~ main.cpp:44:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<val[i].size(); j++) dp[i] = max(dp[i], val[i][j].first + dp[val[i][j].second]); ~^~~~~~~~~~~~~~