Submission #1248588

#	Time	Username	Problem	Language	Result	Execution time	Memory
1248588		qwerasdfzxcl	Tree (IOI24_tree)	C++20	100 / 100	119 ms	65444 KiB

tree

#include "tree.h"
#include <bits/stdc++.h>

using namespace std;
using ll = long long;

constexpr int SZ = 1001000;

int n;
vector<int> adj[200200], buf[SZ+2];
ll a[200200], suf1[SZ+2], suf2[SZ+2], sum;

struct DSU{
    int path[200200], rt[200200];
    ll sum[200200];

    void init(int n){
        for (int i=1;i<=n;i++) path[i] = i, rt[i] = SZ + 1;
    }

    int find(int s){
        if (s==path[s]) return s;
        return path[s] = find(path[s]);
    }

    void toggle(int x, int t, ll v){
        assert(rt[x] == SZ+1);
        rt[x] = t;
        sum[x] = v;
    }

    void push(int x, int t){
        x = find(x);
        suf1[sum[x]] += sum[x] * (rt[x] - t);
        suf2[sum[x]] += rt[x] - t;
        rt[x] = t;
    }

    void merge(int x, int y, int t){
        x = find(x);
        y = find(y);
        if (rt[x]==SZ+1 || rt[y]==SZ+1) return;

        push(x, t);
        push(y, t);

        if (x==y) return;

        path[x] = y;
        sum[y] += sum[x];
    }
}dsu;

void init(std::vector<int> P, std::vector<int> W) {
    n = P.size();
    for (int i=1;i<n;i++) adj[P[i]+1].push_back(i+1);
    for (int i=0;i<n;i++) a[i+1] = W[i];

    for (int i=1;i<=n;i++) if (adj[i].empty()) sum += a[i];

    dsu.init(n);

    for (int i=1;i<=n;i++) if (!adj[i].empty()) buf[a[i]].push_back(i);

    for (int t=SZ-1;t>=0;t--){
        for (auto &x:buf[t]){
            dsu.toggle(x, t, max((int)adj[x].size() - 1, 0));
            dsu.merge(x, P[x-1]+1, t);
            for (auto &y:adj[x]) dsu.merge(x, y, t);
        }
    }

    dsu.push(1, 0);

    for (int i=SZ;i>=0;i--) suf1[i] += suf1[i+1], suf2[i] += suf2[i+1];
}

long long query(int L, int R) {
    return sum * L + suf1[(R-L) / L + 1] * L - suf2[(R-L) / L + 1] * (R-L);
}

• Subtask 0: 0 / 0
• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 18 / 18
• Subtask 4: 7 / 7
• Subtask 5: 11 / 11
• Subtask 6: 22 / 22
• Subtask 7: 19 / 19