제출 #366990

#제출 시각아이디문제언어결과실행 시간메모리
366990PurpleCrayon슈퍼트리 잇기 (IOI20_supertrees)C++17
40 / 100
258 ms22252 KiB
#include "supertrees.h"
#include <bits/stdc++.h>
using namespace std;

#define ar array
#define sz(v) int(v.size())

int n;

struct DSU {
    vector<int> p, sz;
    void init(int n){ sz.assign(n, 1); p.resize(n); iota(p.begin(), p.end(), 0); }
    int find_set(int v){ return v==p[v]?v:p[v]=find_set(p[v]); }
    bool union_sets(int a, int b){
        if ((a=find_set(a))==(b=find_set(b))) return 0;
        if (sz[a] < sz[b]) swap(a, b);
        p[b]=a, sz[a]+=sz[b], sz[b]=0;
        return 1;
    }
} d;

int construct(vector<vector<int>> g) {
	n = sz(g);
    vector<vector<int>> ans(n, vector<int>(n));


    bool done=0, bad=0;

    [&](){ //handle case with a 3
        if (done || bad) return;

        for (int i = 0; i < n; i++) for (int j = 0; j < n; j++) if (g[i][j] == 3) {
            bad=1; return;
        }
    }();

    
    [&](){ //only 1's (tree)
        if (done || bad) return;

        for (int i = 0; i < n; i++) for (int j = i+1; j < n; j++) if (g[i][j] != 1) return;
        for (int i = 1; i < n; i++) ans[i][0] = ans[0][i] = 1;

        build(ans), done=1;
    }();

    [&](){ //0, 1's (just deal with separate comps)
        if (done || bad) return;

        for (int i = 0; i < n; i++) for (int j = i+1; j < n; j++) if (g[i][j] != 0 && g[i][j] != 1) return;

        d.init(n);
        for (int i = 0; i < n; i++) for (int j = i+1; j < n; j++) if (g[i][j])
            if (d.union_sets(i, j)) ans[i][j] = ans[j][i] = 1;

        for (int i = 0; i < n; i++) for (int j = i+1; j < n; j++)
            if ((d.find_set(i) == d.find_set(j))^bool(g[i][j])) return;

        build(ans), done=1;
    }();

    [&](){ //0, 2's (just deal with separate comps, put everything into cycles instead of trees)
        if (done || bad) return;

        for (int i = 0; i < n; i++) for (int j = i+1; j < n; j++) if (g[i][j] != 0 && g[i][j] != 2) return;

        d.init(n);
        for (int i = 0; i < n; i++) for (int j = i+1; j < n; j++) if (g[i][j])
            d.union_sets(i, j);

        for (int i = 0; i < n; i++) for (int j = i+1; j < n; j++)
            if ((d.find_set(i) == d.find_set(j))^bool(g[i][j])) return;

        vector<vector<int>> comp(n);
        for (int i = 0; i < n; i++) comp[d.find_set(i)].push_back(i);

        for (int i = 0; i < n; i++) if (sz(comp[i]) > 1){
            if (sz(comp[i]) == 2) return;
            for (int j = 0; j < sz(comp[i]); j++){
                int nxt=(j+1)%sz(comp[i]);
                ans[comp[i][j]][comp[i][nxt]] = ans[comp[i][nxt]][comp[i][j]] = 1;
            }
        }

        build(ans), done=1;
    }();

    
    
	return !bad && done;
}
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...