Submission #923177

#	Time	Username	Problem	Language	Result	Execution time	Memory
923177		Dzadzo	Ideal city (IOI12_city)	C++17	100 / 100	159 ms	47048 KiB

city

#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define S second
#define F first
#define pii pair<ll,ll>
#define vi vector <ll>
#define vvi vector <vi>
#define vvvi vector <vvi>
#define vp vector <pii>
#define vvp vector <vp>
#define vb vector <bool>
#define vvb vector <vb>;
#define INF LLONG_MAX
#define MOD 1000000000
#define MAXN 1000000
using namespace std;
vvi adj(MAXN+1);
vi a(MAXN+1);
ll ans=0;
int n;
void dfs(ll v,ll p){
	for (int to:adj[v]){
		if (to==p)continue;
		dfs(to,v);
		a[v]+=a[to];
	}
	ans=(ans+(a[v]*(n-a[v]))%MOD)%MOD;
}
int DistanceSum(int N, int X[], int Y[]){
	n=N;
	vp arr;
	map <pii,ll> m;
	for (ll i=0;i<N;i++)arr.pb({1ll*X[i],1ll*Y[i]});
	sort(arr.begin(),arr.end());
	ll cnt=0;
	ll sz=0;
	for (auto &[x,y]:arr){
		if (!m[{x,y-1}]){
			a[cnt]=sz;
			cnt++;
			sz=1;
			if (m[{x-1,y}]){
				adj[cnt].pb(m[{x-1,y}]);
				adj[m[{x-1,y}]].pb(cnt);
			}
		}else{
			sz++;
			if (m[{x-1,y}] && !m[{x-1,y-1}]){
				adj[cnt].pb(m[{x-1,y}]);
				adj[m[{x-1,y}]].pb(cnt);				
			}
		}
		m[{x,y}]=cnt;
	}
	a[cnt]=sz;
	dfs(1,0);
	arr.clear();
	m.clear();
	cnt=sz=0;
	adj.assign(MAXN+1,{});
	a.assign(MAXN+1,0);
	for (ll i=0;i<N;i++)arr.pb({1ll*Y[i],1ll*X[i]});
	sort(arr.begin(),arr.end());
	for (auto &[y,x]:arr){
		if (!m[{x-1,y}]){
			a[cnt]=sz;
			cnt++;
			sz=1;
			if (m[{x,y-1}]){
				adj[cnt].pb(m[{x,y-1}]);
				adj[m[{x,y-1}]].pb(cnt);
			}
		}else{
			sz++;
			if (m[{x,y-1}] && !m[{x-1,y-1}]){
				adj[cnt].pb(m[{x,y-1}]);
				adj[m[{x,y-1}]].pb(cnt);				
			}
		}
		m[{x,y}]=cnt;
	}
	a[cnt]=sz;
	dfs(1,0);
	return ans;
}

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