Submission #882861

#	Time	Username	Problem	Language	Result	Execution time	Memory
882861		MilosMilutinovic	Wild Boar (JOI18_wild_boar)	C++14	47 / 100	17032 ms	1048576 KiB

wild_boar

#include <bits/stdc++.h>
 
using namespace std;
 
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m, t, l;
  cin >> n >> m >> t >> l;
  vector<vector<pair<int, int>>> g(n);
  for (int i = 0; i < m; i++) {
    int x, y, z;
    cin >> x >> y >> z;
    --x; --y;
    g[x].emplace_back(y, z);
    g[y].emplace_back(x, z);
  }
  vector<int> seq(l);
  for (int i = 0; i < l; i++) {
    cin >> seq[i];
    --seq[i];
  }
  {
    int p, x;
    cin >> p >> x;
    --p; --x;
    seq[p] = x;
  }
  vector<int> deg(n);
  for (int i = 0; i < n; i++) {
    deg[i] = (int) g[i].size();
  }
  vector<vector<int>> idx(n, vector<int>(n));
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < deg[i]; j++) {
      idx[i][g[i][j].first] = j;
    }
  }
  const long long inf = (long long) 1e18;
  vector<vector<vector<vector<long long>>>> dist(n, vector<vector<vector<long long>>>(n));
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      dist[i][j].resize(deg[i]);
      for (int k = 0; k < deg[i]; k++) {
        dist[i][j][k] = vector<long long>(deg[j], inf);
      }
    }
  }
  for (int ver = 0; ver < n; ver++) {
    for (int e = 0; e < deg[ver]; e++) {
      vector<vector<long long>> d(n);
      for (int i = 0; i < n; i++) {
        d[i] = vector<long long>(deg[i], inf);
      }
      int to = g[ver][e].first;
      int w = g[ver][e].second;
      d[to][idx[to][ver]] = w;
      set<tuple<long long, int, int>> st;
      st.emplace(d[to][idx[to][ver]], to, idx[to][ver]);
      vector<int> cnt(n);
      while (!st.empty()) {
        auto it = st.begin();
        int v = get<1>(*it);
        int lst = get<2>(*it);
        st.erase(it);
        cnt[v] += 1;
        if (cnt[v] >= 3) {
          continue;
        }
        for (int i = 0; i < deg[v]; i++) {
          if (i == lst) {
            continue;
          }
          int to = g[v][i].first;
          int w = g[v][i].second;
          if (d[to][idx[to][v]] > d[v][lst] + w) {
            if (d[to][idx[to][v]] != inf) {
              st.erase(st.find({d[to][idx[to][v]], to, idx[to][v]}));
            }
            d[to][idx[to][v]] = d[v][lst] + w;
            st.emplace(d[to][idx[to][v]], to, idx[to][v]);
          }
        }
      }
      for (int i = 0; i < n; i++) {
        for (int j = 0; j < deg[i]; j++) {
          dist[ver][i][e][j] = d[i][j];
        }
      }
    }
  }
  vector<vector<vector<vector<int>>>> good(n, vector<vector<vector<int>>>(n));
  int cnt_edges = 0;
  for (int from = 0; from < n; from++) {
    for (int to = 0; to < n; to++) {
      if (from == to) {
        continue;
      }
      good[from][to].resize(deg[from]);
      vector<int> order(deg[to]);
      iota(order.begin(), order.end(), 0);
      for (int i = 0; i < deg[from]; i++) {
        sort(order.begin(), order.end(), [&](int a, int b) {
          return dist[from][to][i][a] < dist[from][to][i][b]; 
        });
        for (int j = 0; j < min(deg[to], 3); j++) {
          good[from][to][i].push_back(order[j]);
          cnt_edges++;
        }
      }
    }
  }
  assert(cnt_edges <= n * m * 6);
  vector<long long> dp(n, inf);
  for (int i = 0; i < deg[seq[0]]; i++) {
    for (int j = 0; j < deg[seq[1]]; j++) {
      dp[j] = min(dp[j], dist[seq[0]][seq[1]][i][j]);
    }
  }
  vector<long long> new_dp(n);
  vector<long long> val(n);
  for (int p = 2; p < l; p++) {
    for (int i = 0; i < deg[seq[p]]; i++) {
      new_dp[i] = inf;
    }
    for (int i = 0; i < deg[seq[p - 1]]; i++) {
      val[i] = inf;
    }
    for (int i = 0; i < deg[seq[p - 1]]; i++) {
      for (int j = 0; j < deg[seq[p - 1]]; j++) {
        if (i != j) {
          val[i] = min(val[i], dp[j]);
        }
      }
    }
    for (int i = 0; i < deg[seq[p - 1]]; i++) {
      for (int j : good[seq[p - 1]][seq[p]][i]) {
        new_dp[j] = min(new_dp[j], val[i] + dist[seq[p - 1]][seq[p]][i][j]);
      }
    }
    for (int i = 0; i < deg[seq[p]]; i++) {
      dp[i] = new_dp[i];
    }
  }
  long long res = inf;
  for (int i = 0; i < deg[seq.back()]; i++) {
    res = min(res, dp[i]);
  }
  cout << (res == inf ? -1 : res) << '\n';
  return 0;
}

• Subtask 1: 12 / 12
• Subtask 2: 35 / 35
• Subtask 3: 0 / 15
• Subtask 4: 0 / 38