Compilare: user.cpp: In function ‘void solve(int)’: user.cpp:24:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i< v[start].size();i++){ ^ user.cpp:29:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<v[v[start][i]].size();j++){ ^ user.cpp:33:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[start].size();i++){ ^ user.cpp:43:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[start].size();i++){ ^ user.cpp:50:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<v[v[start][i]].size();j++){ ^ user.cpp:55:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[start].size();i++){ ^