Submission #73645

#	Time	Username	Problem	Language	Result	Execution time	Memory
73645		FLDutchman	Ideal city (IOI12_city)	C++14	100 / 100	661 ms	33192 KiB

city

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

typedef int INT;

#define pb push_back
#define int long long
#define fst first
#define snd second
#define FOR(i,l,r) for(int i = (l); i < (r); i++)

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> ii;
typedef vector<ii> vii;

struct edge{
	int v, i;
};

int N;
vii points;
vvi adj;
map<ii, int> idx;
vvi rowgr, colgr;
vii ce, re;
vector<vector<edge>> rg, cg;
vi rowsz, colsz;
vi row, col;
vi vis;

void flood(int u, int c, bool co){
	vis[u] = 1;
	if(co) col[u] = c, colsz[c] ++;
	else row[u] = c, rowsz[c] ++;
	for(int i = co; i < 4; i+= 2) if(adj[u][i] != -1 and !vis[adj[u][i]]) flood(adj[u][i], c, co);
	for(int i = 1-co; i < 4; i+= 2) if(adj[u][i] != -1 and vis[adj[u][i]]) {
		int v = adj[u][i];
		if(v == -1) continue;
		if(co) colgr[c].pb(col[v]), colgr[col[v]].pb(c);
		else rowgr[c].pb(row[v]), rowgr[row[v]].pb(c);
	}
}


int dp[200000][2];
int dfs(int e, int u, int p, bool col){
	int &res = dp[e][col];
	if(res != 0) return res;
	res = col ? colsz[u] : rowsz[u];
	for(edge E : (col ? cg[u] : rg[u]) ) if(E.v != p) res += dfs(E.i, E.v, u, col);
	return res;
}

int dfs(int u, int p, int col){
	//cout << u << " " << p << " " << col << endl;
	if(col) {
		int e = lower_bound(ce.begin(), ce.end(), make_pair(p, u))-ce.begin();
		//cout << (ce[e] == make_pair(u,p)) << endl;
		return dfs(e, u, p, col);
	} else {
		int e = lower_bound(re.begin(),re.end(), make_pair(p,u)) -re.begin();
		//cout << (re[e] == make_pair(u,p)) << endl;
		return dfs(e,u,p,col);
	}
}


int gettot(int u, int tot){
	//cout << u << " " << tot << endl;
	int res = tot;
	vis[u] = 1;
	FOR(i, 0, 4){
		int v = adj[u][i];
		if(v == -1 || vis[v]) continue;
		if(i % 2 == 0) { res += gettot(v, tot - 2*dfs(col[v], col[u], 1) + N);  }
		else res += gettot(v, tot - 2*dfs(row[v], row[u], 0) + N);
	}
	return res;
}

int bfs(int u){
	vis.assign(N, 0);
	int total = 0;
	queue<ii> q;
	q.push({u, 0});
	vis[u] = 1;
	while(!q.empty()){
		ii p = q.front(); q.pop();
		total += p.snd;

		for(int v : adj[p.fst])if(v !=-1 and !vis[v]){
			q.push({v,p.snd+1});
			vis[v] = 1;
		}
	}
	vis.assign(N, 0);
	return total;
}

INT DistanceSum(INT n, INT *X, INT *Y) {
	FOR(i,0,200000) FOR(j,0,2) dp[i][j] = 0;
	N = n;
	adj.assign(N, vi(4, -1));
	FOR(i, 0, N) {points.pb({X[i], Y[i]}); idx[{X[i], Y[i]}] = i+1;}
	FOR(i, 0, N){
		int x = X[i], y = Y[i];
		int neigh;
		if(neigh = idx[{x+1, y}]) adj[i][0] = neigh-1;
		if(neigh = idx[{x, y-1}]) adj[i][1] = neigh-1;
		if(neigh = idx[{x-1, y}]) adj[i][2] = neigh-1;
		if(neigh = idx[{x, y+1}]) adj[i][3] = neigh-1;
	}
	idx.clear();
	int k = 0;
	row.assign(N, -1);
	col.assign(N, -1);
	
	vis.assign(N, 0);
	FOR(i, 0, N) if(!vis[i]){
		rowgr.pb(vi(0));
		rowsz.pb(0);
		flood(i, k++,0);
	}
	for(auto &v : rowgr){
		sort(v.begin(), v.end());
		v.erase(unique(v.begin(), v.end()), v.end());
	}
	k = 0;


	vis.assign(N, 0);
	FOR(i, 0, N) if(!vis[i]){
		colgr.pb(vi(0));
		colsz.pb(0);
		flood(i, k++,1);
	}

	vis.assign(N, 0);

	for(auto &v : colgr){
		sort(v.begin(), v.end());
		v.erase(unique(v.begin(), v.end()), v.end());
	}
	rg.resize(rowgr.size());
	cg.resize(colgr.size());
	int i = 0;
	FOR(u, 0, rowgr.size()){
		FOR(v, 0, rowgr[u].size()){
			rg[u].pb({rowgr[u][v], i++});
			re.pb({u, rowgr[u][v]});
		}
	}

	i = 0;
	FOR(u, 0, colgr.size()){
		FOR(v, 0, colgr[u].size()){
			cg[u].pb({colgr[u][v], i++});
			ce.pb({u, colgr[u][v]});
		}
	}

	/*
	cout<<i<<endl;


	for(auto &v : adj) {
		for(int k : v) cout << k << " ";
		cout<<endl;
	}

	for(auto &v : colgr) {
		for(int k : v) cout << k << " ";
		cout<<endl;
	}
	cout<<endl;
	for(auto &v : rowgr) {
		for(int k : v) cout << k << " ";
		cout<<endl;
	}

	for(int k : col) cout << k << " ";
	cout<<endl;
	for(int k : row) cout << k << " ";
	cout<<endl;
	cout << dfs(1, 0, 0) << endl;
	cout << bfs(4) <<endl;
	cout << "bfs " + to_string(dfs(3,4,1)) <<endl;

	*/
  	return (gettot(0, bfs(0))/2) % 1000000000;
}


/*-1 -1 -1 1 
3 0 -1 -1 
4 -1 -1 -1 
7 -1 1 -1 
8 -1 2 5 
9 4 -1 6 
-1 5 -1 7 
10 6 3 -1 
-1 -1 4 9 
-1 8 5 -1 
-1 -1 7 -1 
2 
3 
0 3 
1 2 4 5 
3 
3 

1 
0 4 
3 
2 4 
1 3 
0 0 1 2 3 3 3 3 4 4 5 
0 1 2 1 2 3 4 1 2 3 1 
10
45
0 45
1 36
3 29
7 24
10 33
5 3
6 23
5 24
9 31
8 36
4 29
2 38
1 3
3 4
4 3
3 2
2 0


*/

Compilation message (stderr)

city.cpp: In function 'INT DistanceSum(INT, INT*, INT*)':
city.cpp:109:12: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   if(neigh = idx[{x+1, y}]) adj[i][0] = neigh-1;
city.cpp:110:12: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   if(neigh = idx[{x, y-1}]) adj[i][1] = neigh-1;
city.cpp:111:12: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   if(neigh = idx[{x-1, y}]) adj[i][2] = neigh-1;
city.cpp:112:12: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   if(neigh = idx[{x, y+1}]) adj[i][3] = neigh-1;
city.cpp:10:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define FOR(i,l,r) for(int i = (l); i < (r); i++)
                                       ^
city.cpp:148:2: note: in expansion of macro 'FOR'
  FOR(u, 0, rowgr.size()){
  ^~~
city.cpp:10:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define FOR(i,l,r) for(int i = (l); i < (r); i++)
                                       ^
city.cpp:149:3: note: in expansion of macro 'FOR'
   FOR(v, 0, rowgr[u].size()){
   ^~~
city.cpp:10:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define FOR(i,l,r) for(int i = (l); i < (r); i++)
                                       ^
city.cpp:156:2: note: in expansion of macro 'FOR'
  FOR(u, 0, colgr.size()){
  ^~~
city.cpp:10:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define FOR(i,l,r) for(int i = (l); i < (r); i++)
                                       ^
city.cpp:157:3: note: in expansion of macro 'FOR'
   FOR(v, 0, colgr[u].size()){
   ^~~

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