Submission #830452

#	Time	Username	Problem	Language	Result	Execution time	Memory
830452		pavement	Split the Attractions (IOI19_split)	C++17	0 / 100	410 ms	1048576 KiB

split

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

#define mp make_pair
#define pb push_back

int sz[100005], par[100005], out[100005];
bool vis[100005];
vector<int> adj[100005];

int get_sz(int u, int e = -1) {
	sz[u] = 1;
	for (auto v : adj[u]) if (v != e) {
		par[v] = u;
		sz[u] += get_sz(v, u);
	}
	return sz[u];
}

void mark_all(int u, int col, int e = -1) {
	out[u] = col;
	for (auto v : adj[u]) if (v != e) {
		mark_all(v, col, u);
	}
}

vector<int> find_split(int n, int a, int b, int c, vector<int> p, vector<int> q) {
	int m = (int)p.size();
	for (int i = 0; i < m; i++) {
		adj[p[i]].pb(q[i]);
		adj[q[i]].pb(p[i]);
	}
	get_sz(0);
	int root = -1, split_point = -1;
	for (int i = 0; i < n; i++) {
		for (auto [d, col] : {mp(&a, 1), mp(&b, 2), mp(&c, 3)}) {
			if (sz[i] == *d) {
				root = 0;
				split_point = i;
				mark_all(i, col, par[i]);
				*d = 0;
				break;
			}
			if (n - sz[i] == *d) {
				root = i;
				split_point = par[i];
				mark_all(par[i], col, i);
				*d = 0;
				break;
			}
		}
	}
	if (root == -1) {
		return vector<int>(n, 0);
	}
	queue<int> Q;
	int cnt = 0;
	Q.push(root);
	while (!Q.empty()) {
		int u = Q.front();
		Q.pop();
		for (auto v : adj[u]) if (!vis[v] && v != split_point) {
			vis[v] = 1;
			Q.push(v);			
			cnt++;
			if (cnt == max({a, b, c})) {
				for (int i = 0; i < n; i++) {
					if (vis[i]) {
						out[i] = max({mp(a, 1), mp(b, 2), mp(c, 2)}).second;
					}
				}
				goto done;
			}
		}
	}
	done:;
	set<int> used;
	for (int i = 0; i < n; i++) {
		if (out[i]) {
			used.insert(out[i]);
		}
	}
	assert((int)used.size() == 2);
	int tmp = 0;
	for (int i : used) {
		tmp ^= i;
	}
	for (int i = 0; i < n; i++) {
		if (out[i] == 0) {
			out[i] = tmp;
		}
	}
	vector<int> real_out;
	for (int i = 0; i < n; i++) {
		real_out.pb(out[i]);
	}
	return real_out;
}

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