Submission #587876

#	Time	Username	Problem	Language	Result	Execution time	Memory
587876		lcj	Split the Attractions (IOI19_split)	C++17	40 / 100	89 ms	16524 KiB

split

#include <bits/stdc++.h>
#define fi first
#define se second

using namespace std;

typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;

vector<vector<int>> adj;
vector<pii> subtrees;
vector<int> par;
vector<int> num;
int cnt = 0;

int dfs(int cn, int pr) {
	num[cn] = cnt++;
	par[cn] = pr;
    int su = 1;
    for (int nn : adj[cn]) {
        if (num[nn] != -1 && num[nn] < num[cn]) continue;
        su += dfs(nn, cn);
    }
    subtrees.push_back({su, cn});
    return su;
}
vector<int> flag;

void flag_arb(int cn, int &rem, int fl, bool enf = 0) {
    if (rem == 0) return;
    flag[cn] = fl;
    rem--;
    for (int nn : adj[cn]) {
        if (enf && num[nn] < num[cn]) continue;
        if (flag[nn] != 3) continue;
        flag_arb(nn, rem, fl);
    }
}

vector<int> find_split(int n, int a, int b, int c, vector<int> p, vector<int> q) {
    adj.assign(n, {});
    par.assign(n, -1);
    flag.assign(n, 3);
	num.assign(n, -1);
    for (int i = 0; i < (int)p.size(); i++)
    {
        adj[p[i]].push_back(q[i]);
        adj[q[i]].push_back(p[i]);
    }
    
	vector<int> res(n, 0);
    bool dfl = 0;
    dfs(0, -1);
    for (pii i : subtrees) {
        if (i.fi >= a && n-i.fi >= b) {
            int rem = a;
            flag_arb(i.se, rem, 1, 1);
            rem = b;
            flag_arb(par[i.se], rem, 2);
            dfl = 1;
            break;
        }
        if (i.fi >= b && n-i.fi >= a) {
            int rem = b;
            flag_arb(i.se, rem, 2, 1);
            rem = a;
            flag_arb(par[i.se], rem, 1);
            dfl = 1;
            break;
        }
    }
    if (dfl) {
        res = flag;
    }
	return res;
}

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 22 / 22
• Subtask 4: 0 / 24
• Subtask 5: 0 / 36