Submission #428358

#	Time	Username	Problem	Language	Result	Execution time	Memory
428358		MarcoMeijer	Connecting Supertrees (IOI20_supertrees)	C++14	100 / 100	315 ms	22236 KiB

supertrees

#include "supertrees.h"
#include <bits/stdc++.h>
using namespace std;

// macros
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define FOR(a,b) for(auto& a : b)
#define all(a) a.begin(), a.end()
#define INF 1e9
#define EPS 1e-9
#define pb push_back
#define popb pop_back
#define fi first
#define se second
#define sz size()
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

const int MX=2000;

int n;
struct DSU {
    int p[MX], r[MX];
    vi dif[MX];
    void build() {
        RE(i,n) p[i]=i, r[i]=0, dif[i]={i};
    }
    int get(int i) {return i==p[i] ? i : p[i]=get(p[i]);}
    bool isSame(int i, int j) {return get(i) == get(j);}
    void link(int i, int j) {
        i = get(i), j = get(j);
        if(dif[i].size() > dif[j].size()) swap(i,j);
        FOR(x,dif[i]) dif[j].pb(x);
        if(i != j) {
            if(r[i] > r[j]) {
                p[j] = i;
                swap(dif[i],dif[j]);
            } else {
                p[i] = j;
                if(r[i] == r[j]) r[j]++;
            }
        }
    }
} dsu1, dsu2;

int construct(vector<vi> p) {
	n = p.size();
    vector<vi> answer(n,vi(n,0));

    dsu1.build();
    RE(i,n) RE(j,n) {
        if(p[i][j] == 1 && !dsu1.isSame(i,j))
            dsu1.link(i,j), answer[i][j] = answer[j][i] = 1;
    }
    RE(i,n) RE(j,n) if(p[i][j] == 0 && dsu1.isSame(i,j)) return 0;
    
    dsu2.build();
    RE(i,n) RE(j,n) {
        if(p[i][j] == 2 && !dsu2.isSame(dsu1.get(i),dsu1.get(j)))
            dsu2.link(dsu1.get(i),dsu1.get(j));
    }

    RE(i,n) if(dsu2.get(i) == i) {
        if(dsu2.dif[i].size() == 1)
            continue;
        if(dsu2.dif[i].size() == 2)
            return 0;
        RE(u,dsu2.dif[i].size()) {
            int v = (u+1)%dsu2.dif[i].size();
            int x = dsu2.dif[i][u];
            int y = dsu2.dif[i][v];
            answer[x][y] = answer[y][x] = 1;
        }
    }

    RE(i,n) RE(j,n) if(p[i][j] == 0 && dsu2.isSame(dsu1.get(i),dsu1.get(j))) return 0;
    RE(i,n) RE(j,n) if(p[i][j] == 3) return 0;

	build(answer);
	return 1;
}

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