Compilare: user.cpp: In function ‘int main()’: user.cpp:26:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<V[1].size();++i) dp[V[1][i].first][V[1][i].second]=viz[V[1][i].first][V[1][i].second]=1; ^ user.cpp:29:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<V[i].size();++j) ^ user.cpp:37:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<V[i-1].size();++j) ^ user.cpp:39:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<V[i].size();++j) ^ user.cpp:42:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<V[m].size();++i) ^