Submission #953078

#	Time	Username	Problem	Language	Result	Execution time	Memory
953078		WonderfulWhale	IOI Fever (JOI21_fever)	C++17	0 / 100	1 ms	348 KiB

fever

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

#define int int64_t
#define pb push_back
#define pii pair<int, int>
#define st first
#define nd second
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()

int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};

pii tab[10];
int dir[10];
int dis[10];
bool vis[10];
int n;

int ans = 0;

void dijkstra() {
	// for(int i=0;i<n;i++) cerr << dir[i] << " ";
	// cerr << "\n";
	fill(dis, dis+n, 1e9);
	memset(vis, 0, sizeof(vis));
	dis[0] = 0;
	int cnt = 0;
	for(int i=0;i<n;i++) {
		pii cand = {1e9, -1};
		for(int j=0;j<n;j++) {
			if(vis[j]) continue;
			cand = min(cand, {dis[j], j});
		}
		// cerr << cand.st << " " << cand.nd << "\n";
		if(cand.nd==-1) break;
		cnt++;
		vis[cand.nd] = true;
		int x = cand.nd;
		for(int j=0;j<n;j++) {
			if(vis[j]) continue;
			int y = j;
			int d1 = abs(tab[x].st-tab[y].st);
			int d2 = abs(tab[x].nd-tab[y].nd);
			if(d1!=d2) continue;
			pii p1 = {tab[x].st+dx[dir[x]]*d1, tab[x].nd+dy[dir[x]]*d1};
			pii p2 = {tab[y].st+dx[dir[y]]*d1, tab[y].nd+dy[dir[y]]*d1};
			if(p1!=p2) continue;
			dis[y] = min(dis[y], d1);
		}
	}
	// cerr << cnt << "\n";
	ans = max(ans, cnt);
}

int32_t main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	cin >> n;
	for(int i=0;i<n;i++) {
		cin >> tab[i].st >> tab[i].nd;
	}
	for(int i=0;i<(1<<(2*n));i++) {
		for(int j=0;j<2*n;j+=2) {
			bool a = i&(1<<j);
			bool b = i&(1<<(j+1));
			dir[j/2] = 2*a+b;
		}
		dijkstra();
	}
	cout << ans << "\n";
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 8
• Subtask 3: 0 / 6
• Subtask 4: 0 / 6
• Subtask 5: 0 / 12
• Subtask 6: 0 / 32
• Subtask 7: 0 / 31