# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
1014632 | t_holl | Rail (IOI14_rail) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
#define int long long
#define MULTITEST false
using namespace std;
using idata = vector<int>;
using igrid = vector<idata>;
igrid roads;
idata bfs_states; int i_state = 0;
idata distances;
int bfs (int start) {
i_state ++;
int cnt = 1;
queue<int> q; q.push(start);
bfs_states[start] = i_state;
distances [start] = 0;
while (q.size() != 0) {
int curr = q.front();
q.pop();
for (int next : roads[curr]) {
if (bfs_states[next] == i_state) continue ;
bfs_states[next] = i_state;
distances [next] = distances[curr] + 1;
q.push(next);
cnt ++;
}
}
if (cnt == 0) return 1e18;
int res = 0;
for (int u : distances) res += u + 1;
return res;
}
void solve () {
int N;
cin >> N;
roads .resize(N);
distances .resize(N);
bfs_states.resize(N);
for (int i = 0; i < N; i ++) {
int k; cin >> k;
for (int j = 0; j < k; j ++) {
int n; cin >> n;
roads[n - 1].push_back(i);
}
}
int res = 1e18;
for (int i = 0; i < N; i ++) res = min(res, bfs(i));
cout << res << "\n";
}
signed main () {
ios_base::sync_with_stdio(false); cin.tie(NULL);
int T = 1;
if (MULTITEST) cin >> T;
for (int t = 0; t < T; t ++) solve();
}