Submission #622403

#	Time	Username	Problem	Language	Result	Execution time	Memory
622403		happypotato	Connecting Supertrees (IOI20_supertrees)	C++17	56 / 100	234 ms	26072 KiB

supertrees

#include "supertrees.h"
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int, int>
#define ff first
#define ss second
#define pb push_back
//
const int mxN = 1001;
vector<vector<int>> paths;
int n;
bool vis[mxN];
void resetvis() {
    for (int i = 0; i < n; i++) vis[i] = false;
}
vector<vector<int>> components;
vector<int> curcomponent;
void dfs(int u, int tar) {
    curcomponent.pb(u);
    vis[u] = true;
    for (int v = 0; v < n; v++) {
        if (u != v && 1 <= paths[u][v] && paths[u][v] <= tar && !vis[v]) {
            dfs(v, tar);
        }
    }
}
int rep[mxN];
int repcnt = 1;
bool fullsol() {
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (paths[i][j] == 3) return false;
        }
    }
    for (int i = 0; i < n; i++) {
        if (!vis[i]) {
            dfs(i, 2);
            for (int &x : curcomponent) rep[x] = repcnt;
            repcnt++;
            components.pb(curcomponent);
            curcomponent.clear();
        }
    }
    for (int u = 0; u < n; u++) {
        for (int v = 0; v < n; v++) {
            if (rep[u] == rep[v] && paths[u][v] == 0) return false;
            if (rep[u] != rep[v] && paths[u][v] != 0) return false;
        }
    }
    for (int i = 0; i < n; i++) rep[i] = 0;
    repcnt = 1;
    resetvis();
    vector<vector<int>> ans(n);
    for (int i = 0; i < n; i++) ans[i].resize(n, 0);
    vector<vector<int>> decomp;
    for (vector<int> &cur : components) {
        decomp.clear();
        for (int &u : cur) {
            for (int &v : cur) {
                if (u == v) continue;
                if (!vis[u] && paths[u][v] == 1) {
                    dfs(u, 1);
                    for (int &x : curcomponent) rep[x] = repcnt;
                    repcnt++;
                    decomp.pb(curcomponent);
                    curcomponent.clear();
                    break;
                }
            }
            if (!vis[u]) {
                decomp.pb({u});
                rep[u] = repcnt++;
                vis[u] = true;
            }
        }
        // cerr << "debug rep: ";
        // for (int i = 0; i < n; i++) cerr << rep[i] << ' ';
        // cerr << endl;
        for (int &u : cur) {
            for (int &v : cur) {
                if (paths[u][v] != 1 + (rep[u] != rep[v])) return false;
            }
        }
        for (vector<int> &process : decomp) {
            if (process.size() >= 2) {
                for (int i = 1; i < int(process.size()); i++) {
                    ans[process[i - 1]][process[i]] = 1;
                }
            }
        }
        if (decomp.size() >= 2) {
            for (int i = 1; i < int(decomp.size()); i++) {
                ans[decomp[i - 1][0]][decomp[i][0]] = 1;
            }
            ans[decomp.front()[0]][decomp.back()[0]] = 1;
        }
    }
    for (int u = 0; u < n; u++) {
        for (int v = 0; v < n; v++) {
            ans[u][v] |= ans[v][u];
            ans[v][u] |= ans[u][v];
        }
    }
    build(ans);
    return true;
}
int construct(vector<vector<int>> p) {
    n = p.size(); paths = p;
    return fullsol();
}

• Subtask 1: 11 / 11
• Subtask 2: 10 / 10
• Subtask 3: 0 / 19
• Subtask 4: 35 / 35
• Subtask 5: 0 / 21
• Subtask 6: 0 / 4