제출 #800079

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
800079		PixelCat	슈퍼트리 잇기 (IOI20_supertrees)	C++14	21 / 100	161 ms	24144 KiB

supertrees

#include "supertrees.h"

#ifdef NYAOWO
#include "grader.cpp"
#endif

#include <bits/stdc++.h>
#define For(i, a, b) for(int i = a; i <= b; i++)
#define Forr(i, a, b) for(int i = a; i >= b; i--)
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define sz(x) ((int)x.size())
#define eb emplace_back
// #define int LL
using namespace std;
using LL = long long;
using pii = pair<int, int>;

const int MAXN = 1000;

vector<vector<int>> answer;
inline void add_edge(int a, int b) {
    answer[a][b] = answer[b][a] = 1;
}

struct DSU {
    int p[MAXN + 10];
    void init() {
        memset(p, -1, sizeof(p));
    }
    int find(int n) {
        if(p[n] < 0) return n;
        return p[n] = find(p[n]);
    }
    bool uni(int a, int b) {
        a = find(a); b = find(b);
        if(a == b) return false;
        p[b] = a;
        return true;
    }
    bool same(int a, int b) {
        return find(a) == find(b);
    }
    bool lead(int n) {
        return p[n] < 0;
    }
} dsu;

int construct(vector<vector<int>> p) {
    int n = sz(p);
    For(i, 0, n - 1) For(j, 0, n - 1) if(p[i][j] == 3) return 0;
    answer = vector<vector<int>>(n, vector<int>(n, 0));

    // phase 1: find all CC
    dsu.init();
    For(i, 0, n - 1) For(j, 0, n - 1) {
        if(p[i][j]) dsu.uni(i, j);
    }
    vector<vector<int>> vcc;
    For(i, 0, n - 1) if(dsu.lead(i)) {
        vcc.eb();
        For(j, 0, n - 1) if(dsu.same(i, j)) {
            vcc.back().eb(j);
        }
    }

    // phase 2: solve for each CC
    for(vector<int> &cc:vcc) {
        int mask = 0;
        for(auto &v1:cc) for(auto &v2:cc) {
            mask |= (1 << p[v1][v2]);
        }
        if(mask & 1) return 0;
        if(mask == 2) {
            int rt = cc.back();
            cc.pop_back();
            for(auto &i:cc) {
                add_edge(i, rt);
            }
        } else if(mask == 4) {
            For(i, 1, sz(cc) - 1) {
                add_edge(cc[i], cc[i - 1]);
            }
            add_edge(cc.front(), cc.back());
        }
    }

    build(answer);
    return 1;
}

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