Submission #367257

#	Time	Username	Problem	Language	Result	Execution time	Memory
367257		wind_reaper	이상적인 도시 (IOI12_city)	C++17	0 / 100	20 ms	2540 KiB

city

#include <bits/stdc++.h>

using namespace std;

const int64_t mod = 1e9;

vector<vector<int>> adj;
vector<int64_t> d, c, ans;
vector<pair<int, int>> del = {{-1, 0}, {0, -1}, {1, 0}, {0, 1}};
void dfs(int node, int par){
	for(int v : adj[node]){
		if(v == par)
			continue;
		dfs(v, node);
		c[node] += c[v] + 1;
		d[node] += d[v] + c[v] + 1;
	}
}

void calc(int node, int par, int N){
	if(node == 0) ans[node] = d[node];
	else ans[node] = ans[par] - 2*c[node] + N - 2;

	for(int v : adj[node]){
		if(v == par) continue;
		calc(v, node, N);
	}
}
int DistanceSum(int N, int *X, int *Y) {
	adj.resize(N);
	vector<array<int, 2>> P(N);
	for(int i = 0; i < N; i++)
		P[i] = {X[i], Y[i]};

	sort(P.begin(), P.end());
	vector<int> vis(N, 0);

	queue<array<int, 3>> q;
	q.push({P[0][0], P[0][1], 0});
	vis[0] = 1;
	while(!q.empty()){
		array<int, 3> cur = q.front();
		int x = cur[0], y = cur[1], idx = cur[2];
		q.pop();

		for(auto &[dx, dy] : del){
			array<int, 2> t = {x+dx, y+dy};
			auto it = lower_bound(P.begin(), P.end(), t);
			int tmp = distance(P.begin(), it);
			array<int, 2> temp = P[tmp];
			if(temp[0] == x+dx && temp[1] == y+dy){
				if(!vis[tmp]){
					vis[tmp] = 1;
					adj[tmp].push_back(idx);
					adj[idx].push_back(tmp);
					array<int, 3> p = {temp[0], temp[1], tmp};
					q.push(p);
				}
			}
		}
	}

	d.resize(N), ans.resize(N), c.resize(N);
	dfs(0, 0);
	calc(0, 0, N);
	int64_t f = 0; 
  
	for(int i = 0; i < N; i++)
		(f += ans[i]) %= mod;

	return f/2;
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 21
• Subtask 3: 0 / 23
• Subtask 4: 0 / 45