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Submission #221419

# Submission time Handle Problem Language Result Execution time Memory
221419 2020-04-10T02:51:50 Z rama_pang Wild Boar (JOI18_wild_boar) C++14
47 / 100
 14097 ms 409460 KB 
#include <bits/stdc++.h>
using namespace std;
using lint = long long;

const int MAXN = 2005;
const int MAXM = 4005;
const int MAXL = 100005;
const lint INF = 1e18;

struct edge_t {
  int u, v, w; // u = from, v = to, w = weight
  edge_t() {}
  edge_t(int u, int v, int w) : u(u), v(v), w(w) {}
};

int N, M, T, L;

namespace ShortestPath {

vector<edge_t> edges;
vector<int> adj[MAXN];

// Distance[X][Y][Use Y?] = Shortest Path from edges[X].u to edges[Y].v given we must use X and we must use/not use Y
lint Distance[MAXM][MAXM][2];
int LastEdgeDistance[MAXM][MAXM][2]; // last edge used in Distance[][][]

// ShortestPathEdge[X][edges[Y].v] = Y that has the shortest distance given that we have to use edge X to reach edges[Y].v
int ShortestPathEdge[MAXM][MAXN]; 

void Read() {
  M = M * 2;
  for (int i = 0; i < (M / 2); i++) {
    int A, B, C;
    cin >> A >> B >> C;
    A--, B--;

    adj[A].emplace_back(edges.size());
    edges.emplace_back(A, B, C);

    adj[B].emplace_back(edges.size());
    edges.emplace_back(B, A, C);
  }
}

void Dijkstra(int X) { // Finds all Distance[X][][1][1]
  priority_queue<pair<lint, int>, vector<pair<lint, int>>, greater<pair<lint, int>>> pq;
  pq.emplace(edges[X].w, X);
  Distance[X][X][1] = edges[X].w; // from edges[X].u to edges[X].v

  // Run Dijkstra to find Distance[X][][1][1].
  // Make sure we do not do a U-turn.

  while (!pq.empty()) {
    int cur = pq.top().second;
    lint cur_dist = pq.top().first; 
    pq.pop();

    if (cur_dist != Distance[X][cur][1]) continue;
    int u = edges[cur].v;

    for (auto nxt : adj[u]) {
      if (cur == (nxt ^ 1)) continue; // We cannot U-turn back
      lint &nxt_dist = Distance[X][nxt][1];

      if (nxt_dist == -1 || nxt_dist > cur_dist + edges[nxt].w) {
        nxt_dist = cur_dist + edges[nxt].w;
        pq.emplace(nxt_dist, nxt);
      }
    }
  }
}

void Solve() { // Computes Distance[][][][] and ShortestPathEdge[][][]
  memset(Distance, -1, sizeof(Distance));
  memset(LastEdgeDistance, -1, sizeof(LastEdgeDistance));
  memset(ShortestPathEdge, -1, sizeof(ShortestPathEdge));

  // Computes Distance[][][1] and ShortestPathEdge[][]
  for (int X = 0; X < M; X++) {
    Dijkstra(X);
    for (int Y = 0; Y < M; Y++) {
      if (Distance[X][Y][1] == -1) continue;
      LastEdgeDistance[X][Y][1] = Y;
      int V = edges[Y].v;
      int &SPE = ShortestPathEdge[X][V];
      if (SPE == -1 || Distance[X][SPE][1] > Distance[X][Y][1]) {
        SPE = Y;
      }
    }
  }

  // Computes Distance[][][0]
  for (int X = 0; X < M; X++) {
    vector<multiset<pair<lint, int>>> VertexDist(N);
    for (int Y = 0; Y < M; Y++) {
      VertexDist[edges[Y].v].emplace(Distance[X][Y][1], LastEdgeDistance[X][Y][1]);
    }
    for (int Y = 0; Y < M; Y++) {
      auto it = VertexDist[edges[Y].v].find({Distance[X][Y][1], LastEdgeDistance[X][Y][1]});
      VertexDist[edges[Y].v].erase(it);
      if (!VertexDist[edges[Y].v].empty()) {
        Distance[X][Y][0] = begin(VertexDist[edges[Y].v])->first;
        LastEdgeDistance[X][Y][0] = begin(VertexDist[edges[Y].v])->second;
      }
      VertexDist[edges[Y].v].emplace(Distance[X][Y][1], LastEdgeDistance[X][Y][1]);
    }
  }
}

}

namespace DynamicProgramming {

int X[MAXL];

void Read() {
  for (int i = 0; i < L; i++) {
    cin >> X[i];
    X[i]--;
  }

  // T = 1
  int P, Q;
  cin >> P >> Q;
  X[--P] = --Q;
}

long long Solve() {
  vector<long long> dp(M, INF), next_dp(M, INF);

  // Special Case for pos = 0
  for (auto i : ShortestPath::adj[X[0]]) {
    for (int j = 0; j < M; j++) {
      if (ShortestPath::edges[j].v == X[1] && ShortestPath::Distance[i][j][1] != -1) {
        dp[j] = min(dp[j], ShortestPath::Distance[i][j][1]);
      }
    }
  }

  for (int pos = 1; pos < L - 1; pos++) {
    for (int last_edge = 0; last_edge < M; last_edge++) {
      if (ShortestPath::edges[last_edge].v != X[pos]) continue;

      int nxt_edge = ShortestPath::ShortestPathEdge[last_edge][X[pos + 1]];
      if (nxt_edge == -1) continue;

      next_dp[nxt_edge] = min(next_dp[nxt_edge], 
        dp[last_edge] + ShortestPath::Distance[last_edge][nxt_edge][1] - ShortestPath::edges[last_edge].w);
      
      int exclude_nxt_edge = ShortestPath::LastEdgeDistance[last_edge][nxt_edge][0];
      if (exclude_nxt_edge == -1) continue;
      next_dp[exclude_nxt_edge] = min(next_dp[exclude_nxt_edge], 
        dp[last_edge] + ShortestPath::Distance[last_edge][exclude_nxt_edge][1] - ShortestPath::edges[last_edge].w);
    }

    dp = next_dp;
    next_dp.assign(M, INF);
  }

  long long res = *min_element(begin(dp), end(dp));
  if (res == INF) res = -1;
  return res;
}

}

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0), cout.tie(0);

  cin >> N >> M >> T >> L;

  ShortestPath::Read();
  ShortestPath::Solve();
  
  DynamicProgramming::Read();
  cout << DynamicProgramming::Solve() << "\n";

  return 0;
}

Subtask #1
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 212 ms 408444 KB Output is correct
2 Correct 211 ms 408656 KB Output is correct
3 Correct 223 ms 408508 KB Output is correct
4 Correct 207 ms 408440 KB Output is correct
5 Correct 216 ms 408568 KB Output is correct
6 Correct 225 ms 408440 KB Output is correct
7 Correct 207 ms 408440 KB Output is correct
8 Correct 211 ms 408648 KB Output is correct
9 Correct 213 ms 408440 KB Output is correct
10 Correct 215 ms 408440 KB Output is correct
11 Correct 212 ms 408592 KB Output is correct
12 Correct 211 ms 408440 KB Output is correct
13 Correct 210 ms 408440 KB Output is correct
14 Correct 214 ms 408568 KB Output is correct
15 Correct 213 ms 408440 KB Output is correct
16 Correct 205 ms 408440 KB Output is correct
17 Correct 209 ms 408492 KB Output is correct
18 Correct 208 ms 408444 KB Output is correct
19 Correct 208 ms 408440 KB Output is correct
20 Correct 213 ms 408572 KB Output is correct
21 Correct 211 ms 408440 KB Output is correct
22 Correct 210 ms 408440 KB Output is correct
23 Correct 218 ms 408572 KB Output is correct
24 Correct 225 ms 408440 KB Output is correct
25 Correct 210 ms 408440 KB Output is correct

Subtask #2
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 212 ms 408444 KB Output is correct
2 Correct 211 ms 408656 KB Output is correct
3 Correct 223 ms 408508 KB Output is correct
4 Correct 207 ms 408440 KB Output is correct
5 Correct 216 ms 408568 KB Output is correct
6 Correct 225 ms 408440 KB Output is correct
7 Correct 207 ms 408440 KB Output is correct
8 Correct 211 ms 408648 KB Output is correct
9 Correct 213 ms 408440 KB Output is correct
10 Correct 215 ms 408440 KB Output is correct
11 Correct 212 ms 408592 KB Output is correct
12 Correct 211 ms 408440 KB Output is correct
13 Correct 210 ms 408440 KB Output is correct
14 Correct 214 ms 408568 KB Output is correct
15 Correct 213 ms 408440 KB Output is correct
16 Correct 205 ms 408440 KB Output is correct
17 Correct 209 ms 408492 KB Output is correct
18 Correct 208 ms 408444 KB Output is correct
19 Correct 208 ms 408440 KB Output is correct
20 Correct 213 ms 408572 KB Output is correct
21 Correct 211 ms 408440 KB Output is correct
22 Correct 210 ms 408440 KB Output is correct
23 Correct 218 ms 408572 KB Output is correct
24 Correct 225 ms 408440 KB Output is correct
25 Correct 210 ms 408440 KB Output is correct
26 Correct 222 ms 408612 KB Output is correct
27 Correct 275 ms 408944 KB Output is correct
28 Correct 275 ms 408828 KB Output is correct
29 Correct 533 ms 408952 KB Output is correct
30 Correct 545 ms 409080 KB Output is correct
31 Correct 621 ms 408952 KB Output is correct
32 Correct 642 ms 408952 KB Output is correct
33 Correct 494 ms 408952 KB Output is correct
34 Correct 535 ms 409076 KB Output is correct
35 Correct 644 ms 408952 KB Output is correct
36 Correct 580 ms 408952 KB Output is correct
37 Correct 524 ms 409080 KB Output is correct
38 Correct 492 ms 408932 KB Output is correct
39 Correct 518 ms 408952 KB Output is correct
40 Correct 483 ms 408952 KB Output is correct
41 Correct 495 ms 408952 KB Output is correct
42 Correct 507 ms 409080 KB Output is correct
43 Correct 476 ms 408952 KB Output is correct
44 Correct 486 ms 409232 KB Output is correct
45 Correct 425 ms 408952 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 212 ms 408444 KB Output is correct
2 Correct 211 ms 408656 KB Output is correct
3 Correct 223 ms 408508 KB Output is correct
4 Correct 207 ms 408440 KB Output is correct
5 Correct 216 ms 408568 KB Output is correct
6 Correct 225 ms 408440 KB Output is correct
7 Correct 207 ms 408440 KB Output is correct
8 Correct 211 ms 408648 KB Output is correct
9 Correct 213 ms 408440 KB Output is correct
10 Correct 215 ms 408440 KB Output is correct
11 Correct 212 ms 408592 KB Output is correct
12 Correct 211 ms 408440 KB Output is correct
13 Correct 210 ms 408440 KB Output is correct
14 Correct 214 ms 408568 KB Output is correct
15 Correct 213 ms 408440 KB Output is correct
16 Correct 205 ms 408440 KB Output is correct
17 Correct 209 ms 408492 KB Output is correct
18 Correct 208 ms 408444 KB Output is correct
19 Correct 208 ms 408440 KB Output is correct
20 Correct 213 ms 408572 KB Output is correct
21 Correct 211 ms 408440 KB Output is correct
22 Correct 210 ms 408440 KB Output is correct
23 Correct 218 ms 408572 KB Output is correct
24 Correct 225 ms 408440 KB Output is correct
25 Correct 210 ms 408440 KB Output is correct
26 Correct 222 ms 408612 KB Output is correct
27 Correct 275 ms 408944 KB Output is correct
28 Correct 275 ms 408828 KB Output is correct
29 Correct 533 ms 408952 KB Output is correct
30 Correct 545 ms 409080 KB Output is correct
31 Correct 621 ms 408952 KB Output is correct
32 Correct 642 ms 408952 KB Output is correct
33 Correct 494 ms 408952 KB Output is correct
34 Correct 535 ms 409076 KB Output is correct
35 Correct 644 ms 408952 KB Output is correct
36 Correct 580 ms 408952 KB Output is correct
37 Correct 524 ms 409080 KB Output is correct
38 Correct 492 ms 408932 KB Output is correct
39 Correct 518 ms 408952 KB Output is correct
40 Correct 483 ms 408952 KB Output is correct
41 Correct 495 ms 408952 KB Output is correct
42 Correct 507 ms 409080 KB Output is correct
43 Correct 476 ms 408952 KB Output is correct
44 Correct 486 ms 409232 KB Output is correct
45 Correct 425 ms 408952 KB Output is correct
46 Correct 578 ms 408568 KB Output is correct
47 Incorrect 14097 ms 409460 KB Output isn't correct
48 Halted 0 ms 0 KB -

Subtask #4
0 / 38.0

# Verdict Execution time Memory Grader output
1 Correct 212 ms 408444 KB Output is correct
2 Correct 211 ms 408656 KB Output is correct
3 Correct 223 ms 408508 KB Output is correct
4 Correct 207 ms 408440 KB Output is correct
5 Correct 216 ms 408568 KB Output is correct
6 Correct 225 ms 408440 KB Output is correct
7 Correct 207 ms 408440 KB Output is correct
8 Correct 211 ms 408648 KB Output is correct
9 Correct 213 ms 408440 KB Output is correct
10 Correct 215 ms 408440 KB Output is correct
11 Correct 212 ms 408592 KB Output is correct
12 Correct 211 ms 408440 KB Output is correct
13 Correct 210 ms 408440 KB Output is correct
14 Correct 214 ms 408568 KB Output is correct
15 Correct 213 ms 408440 KB Output is correct
16 Correct 205 ms 408440 KB Output is correct
17 Correct 209 ms 408492 KB Output is correct
18 Correct 208 ms 408444 KB Output is correct
19 Correct 208 ms 408440 KB Output is correct
20 Correct 213 ms 408572 KB Output is correct
21 Correct 211 ms 408440 KB Output is correct
22 Correct 210 ms 408440 KB Output is correct
23 Correct 218 ms 408572 KB Output is correct
24 Correct 225 ms 408440 KB Output is correct
25 Correct 210 ms 408440 KB Output is correct
26 Correct 222 ms 408612 KB Output is correct
27 Correct 275 ms 408944 KB Output is correct
28 Correct 275 ms 408828 KB Output is correct
29 Correct 533 ms 408952 KB Output is correct
30 Correct 545 ms 409080 KB Output is correct
31 Correct 621 ms 408952 KB Output is correct
32 Correct 642 ms 408952 KB Output is correct
33 Correct 494 ms 408952 KB Output is correct
34 Correct 535 ms 409076 KB Output is correct
35 Correct 644 ms 408952 KB Output is correct
36 Correct 580 ms 408952 KB Output is correct
37 Correct 524 ms 409080 KB Output is correct
38 Correct 492 ms 408932 KB Output is correct
39 Correct 518 ms 408952 KB Output is correct
40 Correct 483 ms 408952 KB Output is correct
41 Correct 495 ms 408952 KB Output is correct
42 Correct 507 ms 409080 KB Output is correct
43 Correct 476 ms 408952 KB Output is correct
44 Correct 486 ms 409232 KB Output is correct
45 Correct 425 ms 408952 KB Output is correct
46 Correct 578 ms 408568 KB Output is correct
47 Incorrect 14097 ms 409460 KB Output isn't correct
48 Halted 0 ms 0 KB -