Submission #286818

#	Time	Username	Problem	Language	Result	Execution time	Memory
286818		ChrisT	Tropical Garden (IOI11_garden)	C++17	100 / 100	3092 ms	36548 KiB

garden

#include<bits/stdc++.h>
#include "garden.h"
#include "gardenlib.h"
using namespace std;
void count_routes(int n, int m, int p, int r[][2], int q, int g[]) {
	vector<int> togo(2*n+1,-1);
	for (int i = 0; i < m; i++) {
		auto [a,b] = r[i];
		if (!~togo[2*a]) togo[2*a] = 2*b+(!~togo[2*b]);
		else if (!~togo[2*a+1]) togo[2*a+1] = 2*b+(!~togo[2*b]);
		if (!~togo[2*b]) togo[2*b] = 2*a+(togo[2*a]/2==b);
		else if (!~togo[2*b+1]) togo[2*b+1] = 2*a+(togo[2*a]/2==b);
	}
	n *= 2;
	vector<vector<int>> adj(n+1);
	for (int i = 0; i < n; i++) {
		if (!~togo[i]) togo[i] = togo[i-1];
		adj[togo[i]].push_back(i);
	}
	vector<int> cmp(n+1), dist(n+1), to(n+1,-1), ind(n+1); vector<vector<int>> cyc(n+1); int cc = 0;
	for (int i = 0; i < n; i++) if (!cmp[i]) {
		int cur = i; ++cc;
		while (!cmp[cur]) {
			cmp[cur] = cc, cur = togo[cur];
		}
		int o = cur; queue<int> qq;
		do {
			ind[cur] = (int)cyc[cc].size(); cyc[cc].push_back(cur); to[cur] = cur; qq.push(cur);
		} while ((cur = togo[cur]) != o);
		while (!qq.empty()) {
			int cur = qq.front(); qq.pop();
			for (int j : adj[cur]) if (!~to[j]) {
				to[j] = to[cur]; cmp[j] = cc;
				dist[j] = dist[cur] + 1;
				qq.push(j);
			}
		}
	}
	array<vector<int>,2> temp;
	temp[0].resize(n); temp[1].resize(n);
	for (int i = 2*p; i <= 2*p+1; i++) if (dist[i]) {
		queue<int> qq; qq.push(i); int par = i % 2;
		fill(temp[par].begin(),temp[par].end(),1e9);
		temp[par][i] = 0;
		while (!qq.empty()) {
			int cur = qq.front(); qq.pop();
			for (int j : adj[cur]) if (temp[par][cur] + 1 < temp[par][j]) {
				temp[par][j] = temp[par][cur] + 1;
				qq.push(j);
			}
		}
	}
	for (int i = 0; i < q; i++) {
		int ret = 0, k = g[i];
		for (int i = 0; i < n; i += 2) ret += temp[0][i] == k || temp[1][i] == k || (dist[i] <= k && cyc[cmp[i]][(ind[to[i]] + k - dist[i]) % ((int)cyc[cmp[i]].size())]/2 == p);
		answer(ret);
	}
}

• Subtask 1: 49 / 49
• Subtask 2: 20 / 20
• Subtask 3: 31 / 31