Submission #1018487

#	Time	Username	Problem	Language	Result	Execution time	Memory
1018487		pcc	Ideal city (IOI12_city)	C++17	32 / 100	82 ms	3416 KiB

city

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

#define pii pair<int,int>
#define fs first
#define sc second

const int mod = 1e9;
const int mxn = 1e5+10;
vector<int> paths[mxn];
vector<pii> v;

namespace SUB1{
	int N;
	int dist[mxn];
	queue<int> q;
	int BFS(int now){
		memset(dist,-1,sizeof(dist));
		dist[now] = 0;
		q.push(now);
		while(!q.empty()){
			auto now = q.front();
			q.pop();
			for(auto nxt:paths[now]){
				if(dist[nxt] == -1){
					dist[nxt] = dist[now]+1;
					q.push(nxt);
				}
			}
		}
		int re = 0;
		for(int i = 0;i<N;i++)re = (re+dist[i])%mod;
		return re;
	}
	int GO(int NN,int* xx,int *yy){
		N = NN;
		for(int i = 0;i<N;i++){
			v.push_back(pii(xx[i],yy[i]));
		}
		vector<int> perm;
		for(int i = 0;i<N;i++)perm.push_back(i);
		sort(perm.begin(),perm.end(),[](int a,int b){return v[a].fs == v[b].fs?v[a].sc<v[b].sc:v[a].fs<v[b].fs;});
		for(int i = 1;i<N;i++){
			int now = perm[i],pre = perm[i-1];
			if(v[now].fs == v[pre].fs&&v[now].sc == v[pre].sc+1){
				paths[now].push_back(pre);
				paths[pre].push_back(now);
			}
		}
		sort(perm.begin(),perm.end(),[](int a,int b){return v[a].sc == v[b].sc?v[a].fs<v[b].fs:v[a].sc<v[b].sc;});
		for(int i = 1;i<N;i++){
			int now = perm[i],pre = perm[i-1];
			if(v[now].sc == v[pre].sc&&v[now].fs == v[pre].fs+1){
				paths[now].push_back(pre);
				paths[pre].push_back(now);
			}
		}
		int ans = 0;
		for(int i = 0;i<N;i++){
			ans += BFS(i);
			ans %= mod;
		}
		return ans>>1;
	}
}

namespace SUB2{
	int GO(int NN,int *X,int *Y){
		return -1;
	}
}

int DistanceSum(int N, int *X, int *Y) {
	if(N<=2000)return SUB1::GO(N,X,Y);
	else return SUB2::GO(N,X,Y);
}

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