Submission #83999

#	Time	Username	Problem	Language	Result	Execution time	Memory
83999		aminra	007 (CEOI14_007)	C++17	0 / 100	406 ms	45648 KiB

007

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
const int infint = 1e9;
const int MOD = (int)1e9 + 7;
const int MAXN = (int)1e6 + 7;
int dist1[MAXN], dist2[MAXN], dist3[MAXN], n, m, s, d, a, b;
vector<int> G[MAXN];
void bfs(int s, int type)
{
	if(type == 0)
		dist1[s] = 0;
	else
	if(type == 1)
		dist2[s] = 0;
	else
		dist3[s] = 0;
	queue<int> q;
	q.push(s);
	while(!q.empty())
	{
		int st = q.front();
		q.pop();
		for (auto v : G[st])
		{
			if(type == 0 && dist1[v] == -1)
				dist1[v] = dist1[st] + 1, q.push(v);
			else
			if(type == 1 && dist2[v] == -1)
				dist2[v] = dist2[st] + 1, q.push(v);
			else
			if(type == 2 && dist3[v] == -1)
				dist3[v] = dist3[st] + 1, q.push(v);
		}
	}
}
bool check(int u, int v)
{
	if(dist1[v] < dist1[u] || dist2[v] < dist2[u])
		return 0;
	return 1;
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
	memset(dist1, -1, sizeof dist1);
	memset(dist2, -1, sizeof dist2);
	memset(dist3, -1, sizeof dist3);
	cin >> n >> m >> s >> d >> a >> b;
	for (int i = 0; i < m; i++)
	{
		int u, v;
		cin >> u >> v;
		G[u].push_back(v);
		G[v].push_back(u);
	}
	bfs(a, 0);
	bfs(b, 1);
	bfs(d, 2);
	if(check(s, d) == 0)
		return cout << -1, 0;
	int L = 0, R = n + 1;
	while(R - L > 1)
	{
		int mid = (L + R) >> 1;
		bool c = 1;
		for (int i = 1; i <= n; i++)
			if(dist3[i] <= mid && check(s, i) == 0)
				c = 0;
		if(c)
			L = mid;
		else
			R = mid;	
	}
	cout << L;
}

• Subtask 1: 0 / 30
• Subtask 2: 0 / 70