Submission #218054

#	Time	Username	Problem	Language	Result	Execution time	Memory
218054		AQT	Ideal city (IOI12_city)	C++14	0 / 100	214 ms	6260 KiB

city

#include <bits/stdc++.h>

using namespace std;

int N, C;
vector<int> graph[100005];
int sz[100005];
set<pair<int, int>> st;
map<pair<int, int>, pair<int, int>> par;
vector<pair<int, int>> coords;
map<pair<int, int>, int> who;

pair<int, int> getrt(pair<int, int> n){
	return par[n] = (par[n] == n ? n : getrt(par[n]));
}

void dfs(int n, int p){
	for(int e : graph[n]){
		if(e != p){
			dfs(e, n);
			sz[n] += sz[e];
		}
	}
}

void build(){
	for(auto p : coords){
		par[p] = p;
		if(st.count({p.first-1, p.second})){
			par[getrt({p.first-1, p.second})] = p;
		}
		if(st.count({p.first+1, p.second})){
			par[getrt({p.first+1, p.second})] = p;
		}
		st.insert({p.first, p.second});
	}
	C = 0;
	for(int i = 0; i<N; i++){
		if(par[coords[i]] == coords[i]){
			who[coords[i]] = ++C;
		}
	}
	for(auto p : coords){
		auto n = who[getrt(p)];
		if(st.count({p.first, p.second-1})){
			auto a = who[getrt({p.first, p.second-1})];
			graph[a].push_back(n);
		}
		if(st.count({p.first, p.second+1})){
			auto a = who[getrt({p.first, p.second+1})];
			graph[a].push_back(n);
		}
	}
	for(int i = 1; i<=C; i++){
		sort(graph[i].begin(), graph[i].end());
		graph[i].erase(unique(graph[i].begin(), graph[i].end()), graph[i].end());
	}
}

long long calc(int *X, int *Y){
	for(int i = 0; i<N; i++){
		coords.push_back({X[i], Y[i]});
	}
	build();
	dfs(1, 0);
	long long ans = 0;
	for(int i = 1; i<=C; i++){
		ans += 1LL*sz[i]*(N-sz[i]);
		graph[i].clear();
	}
	coords.clear();
	par.clear();
	st.clear();
	who.clear();
	return ans;
}

int DistanceSum(int NN, int *X, int *Y){
	N = NN;
	long long ret = calc(X, Y);
	ret += calc(Y, X);
	return ret;
}

/*
int main(){
	cin.sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
}
*/

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