Submission #131657

#	Time	Username	Problem	Language	Result	Execution time	Memory
131657		fefe	Ideal city (IOI12_city)	C++17	32 / 100	18 ms	3700 KiB

city

#include<bits/stdc++.h>
#define MAX_N 100005
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define all(v) (v).begin(),(v).end()
using namespace std;
typedef pair<int,int> pii;
int n,m;
int cnt[MAX_N],num[MAX_N];
long long ans;
vector<int> adj[MAX_N];
vector<pii> V;
bool vis[MAX_N];
int dfs(int x){
	vis[x]=true;
	int sum = cnt[x];
	for(int y:adj[x]){
	
		if(vis[y]){
			continue;
		}
		
		sum+=dfs(y);
	}
	ans = (ans + (long long) sum * (n-sum));
	return sum;
}
void solve(){
	int i;
	sort(all(V));
	
	for(i=0;i<n;i++){
		int e=i;
		while(e<n-1 && V[e].fi == V[e+1].fi && V[e].se + 1 == V[e+1].se)	e++;	
		m++;
		for(int j=i;j<=e;j++){
			int x=lower_bound(all(V),make_pair(V[j].fi-1,V[j].se))-V.begin();
			if(V[x] == make_pair(V[j].fi-1,V[j].se)){
				adj[m].eb(num[x]);
				adj[num[x]].eb(m);
			}
			num[j]=m;
			cnt[m]++;
		}		
		i=e;
	}
	
	dfs(1);
	for(i=0;i<n;i++)	num[i]=vis[i]=0;
	for(i=1;i<=m;i++){
		cnt[i]=0;
		adj[i].clear();adj[i].resize(0);
		
	}
	m=0;
	
}
int DistanceSum(int N, int *X, int *Y) {
	
	n=N;
	
	int i;
	
	for(i=0;i<n;i++){
		V.eb(X[i],Y[i]);
	}
	solve();
	
	for(i=0;i<n;i++){
		swap(V[i].fi,V[i].se);
	}
	solve();
	return ans;
}

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