Submission #1301265

#TimeUsernameProblemLanguageResultExecution timeMemory
1301265fanwenFactories (JOI14_factories)C++20
15 / 100
8096 ms132496 KiB
#include <bits/stdc++.h>

using namespace std;

int n, LOG;
vector <vector <pair <int, int>>> adj;

vector <int> depth;
vector <long long> d;
vector <vector <int>> par;

vector <int> time_in, time_out;

int __lca(int u, int v) {
    if(depth[u] < depth[v]) swap(u, v);
    for (int i = LOG; --i >= 0;) {
        if(depth[par[i][u]] >= depth[v]) {
            u = par[i][u];
        }
    }
    if(u == v) return u;
    for (int i = LOG; --i >= 0;) {
        if(par[i][u] != par[i][v]) {
            u = par[i][u];
            v = par[i][v];
        }
    }
    return par[0][u];
}

long long dist(int u, int v) {
    return d[u] + d[v] - 2 * d[__lca(u, v)];
}

bool is_par(int u, int v) { // check u is parent of v 
    return time_in[u] <= time_in[v] and time_in[v] <= time_out[u];
}

void Init(int N, int A[], int B[], int D[]) {
    n = N;
    LOG = 32 - __builtin_clz(n);
    adj = vector <vector <pair <int, int>>> (n + 1);
    for (int i = 0; i < n - 1; ++i) {
        adj[A[i] + 1].emplace_back(B[i] + 1, D[i]);
        adj[B[i] + 1].emplace_back(A[i] + 1, D[i]);
    }
    par = vector <vector <int>> (LOG + 1, vector <int> (n + 1));
    depth = time_in = time_out = vector <int> (n + 1);
    d = vector <long long > (n + 1, 0);
    function <void(int, int)> dfs = [&] (int u, int p) {
        static int run = 0;
        time_in[u] = ++run;
        depth[u] = depth[p] + 1;
        par[0][u] = p;
        for (int i = 1; (1 << i) <= depth[u]; ++i) {
            par[i][u] = par[i - 1][par[i - 1][u]];
        }
        for (auto [v, w] : adj[u]) if(v != p) {
            d[v] = d[u] + w;
            dfs(v, u);
        }
        time_out[u] = run;
    };
    dfs(1, 0);
}

long long Query(int S, int X[], int T, int Y[]) {
    static vector <int> dd(n + 1, -1);
    vector <int> p;
    for (int i = 0; i < S; ++i) {
        p.emplace_back(X[i] + 1);
        dd[X[i] + 1] = 0;
    }    
    for (int i = 0; i < T; ++i) {
        p.emplace_back(Y[i] + 1);
        dd[Y[i] + 1] = 1;
    }
    sort(p.begin(), p.end(), [&] (const int &x, const int &y) {
        return time_in[x] < time_in[y];
    });
    int len = p.size();
    for (int i = 0; i < len - 1; ++i) {
        p.emplace_back(__lca(p[i], p[i + 1]));
    }
    sort(p.begin(), p.end(), [&] (const int &x, const int &y) {
        return time_in[x] < time_in[y];
    });
    p.erase(unique(p.begin(), p.end()), p.end());
    static vector <vector <pair <int, long long>>> adj(n + 1);
    static vector <vector <long long>> dp(n + 1, vector <long long> (2));
    stack <int> st; 
    if(p[0] != 1) st.push(1);
    for (auto u : p) {
        while(not st.empty() and !is_par(st.top(), u)) st.pop();
        if(not st.empty()) adj[st.top()].emplace_back(u, dist(u, st.top()));
        // cout << u << " " << st.top() << endl;
        st.push(u);
    }
    // return 1;
    long long ans = 1e18;
    function <void(int)> dfs = [&] (int u) {
        dp[u][0] = dp[u][1] = 1e18;
        if(dd[u] != -1) {
            dp[u][dd[u]] = 0;
        }
        for (auto [v, w] : adj[u]) {
            dfs(v);
            // cout << u - 1 << " " << v - 1 << " " << w << endl; 
            ans = min(ans, dp[u][0] + w + dp[v][1]);
            ans = min(ans, dp[u][1] + w + dp[v][0]);
            dp[u][0] = min(dp[u][0], dp[v][0] + w);
            dp[u][1] = min(dp[u][1], dp[v][1] + w);
        }
    };
    // for (int i = 1; i <= n; ++i) cout << dp[i][0] << " " << dp[i][1] << endl; 
    dfs(1);

    for (int u : p) {
        dd[u] = -1;
        adj[u].clear();
    }
    return ans; 
}

#ifdef LOCAL 

#include <stdio.h>
#include <stdlib.h>

#define MAX_N          500000
#define MAX_Q          100000
#define MAX_SUM_ST    1000000
#define MAX_VALUE  1000000000

static int N, Q;
static int A[MAX_N], B[MAX_N], D[MAX_N];
static int S[MAX_N];
static int T[MAX_N];
static int X[MAX_SUM_ST];
static int Y[MAX_SUM_ST];

static int Qx[MAX_N];
static int Qy[MAX_N];

int main() {
//   freopen("TASK.inp","r",stdin);

  int i, j, k;
  int STop, TTop;

  if (2 != scanf("%d%d", &N, &Q)) {
    fprintf(stderr, "error: cannot read N and Q.\n");
    exit(1);
  }
  if (!(2 <= N && N <= MAX_N)) {
    fprintf(stderr, "error: N is out of bounds.\n");
    exit(1);
  }
  if (!(1 <= Q && Q <= MAX_Q)) {
    fprintf(stderr, "error: Q is out of bounds.\n");
    exit(1);
  }
  for (i = 0; i < N - 1; ++i) {
    if (1 != scanf("%d", &A[i])) {
      fprintf(stderr, "error: cannot read A[%d].\n", i);
      exit(1);
    }
    if (!(0 <= A[i] && A[i] <= N - 1)) {
      fprintf(stderr, "error: A[%d] is out of bounds.\n", i);
      exit(1);
    }
    if (1 != scanf("%d", &B[i])) {
      fprintf(stderr, "error: cannot read B[%d].\n", i);
      exit(1);
    }
    if (!(0 <= B[i] && B[i] <= N - 1)) {
      fprintf(stderr, "error: B[%d] is out of bounds.\n", i);
      exit(1);
    }
    if (A[i] == B[i]) {
      fprintf(stderr, "error: B[%d] is equal to A[%d].\n", i, i);
      exit(1);
    }
    if (1 != scanf("%d", &D[i])) {
      fprintf(stderr, "error: cannot read D[%d].\n", i);
      exit(1);
    }
    if (!(1 <= D[i] && D[i] <= MAX_VALUE)) {
      fprintf(stderr, "error: D[%d] is out of bounds.\n", i);
      exit(1);
    }
  }

  STop = 0;
  TTop = 0;

  for (j = 0; j < Q; ++j) {
    if (2 != scanf("%d%d", &S[j], &T[j])) {
      fprintf(stderr, "error: cannot read L[%d] and R[%d].\n", j, j);
      exit(1);
    }

    if(STop + S[j] > MAX_SUM_ST) {
      fprintf(stderr, "error: S[0] + S[1] + ... + S[%d] is out of bounds.\n", j);
      exit(1);
    }

    if(TTop + T[j] > MAX_SUM_ST) {
      fprintf(stderr, "error: T[0] + T[1] + ... + T[%d] is out of bounds.\n", j);
      exit(1);
    }

    for (k = 0; k < S[j]; ++k, ++STop) {
      if (1 != scanf("%d", &X[STop])) {
        fprintf(stderr, "error: cannot read X[%d][%d].\n", j, k);
        exit(1);
      }

      if (!(0 <= X[STop] && X[STop] <= N - 1)) {
        fprintf(stderr, "error: cannot read X[%d][%d].\n", j, k);
        exit(1);
      }
    }

    for (k = 0; k < T[j]; ++k, ++TTop) {
      if (1 != scanf("%d", &Y[TTop])) {
        fprintf(stderr, "error: cannot read Y[%d][%d].\n", j, k);
        exit(1);
      }

      if (!(0 <= Y[TTop] && Y[TTop] <= N - 1)) {
        fprintf(stderr, "error: cannot read Y[%d][%d].\n", j, k);
        exit(1);
      }
    }
  }

  STop = 0;
  TTop = 0;
  Init(N, A, B, D);
  
  for (j = 0; j < Q; ++j) {
    for (k = 0; k < S[j]; k++) {
      Qx[k] = X[STop++];
    }
    for (k = 0; k < T[j]; k++) {
      Qy[k] = Y[TTop++];
    }
    
    printf("%lld\n", Query(S[j], Qx, T[j], Qy));
  }


  return 0;
}

#endif 
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