Compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:84:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(it[node] = 0; it[node] < tree[node].size(); it[node] ++) { ^ user.cpp:139:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(it[node] = 0; it[node] < tree[node].size(); it[node] ++) { ^ user.cpp: In function ‘void ReadInput()’: user.cpp:55:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:58:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int u, v, d; scanf("%d%d%d", &u, &v, &d); ^ user.cpp:64:57: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &times[i].first, &times[i].second); ^