Submission #1311180

#	Time	Username	Problem	Language	Result	Execution time	Memory
1311180		PlayVoltz	Seats (IOI18_seats)	C++20	100 / 100	3958 ms	172672 KiB

seats

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

#define pii pair<int,int>
#define mp make_pair
#define pb push_back
#define fi first
#define se second

int h, w, n;
vector<pii> vect;
vector<vector<int> > graph;

struct node{
	int s, e, m, lazy;
	pii val;
	node *l, *r;
	void propagate(){
		val.fi+=lazy;
		if (s!=e){
			l->lazy+=lazy;
			r->lazy+=lazy;
		}
		lazy=0;
	}
	node(int S, int E){
		s = S, e = E, m = (s+e)/2;
		val.fi=lazy=0;
		val.se=e-s+1;
		if (s!=e){
			l = new node(s, m);
			r = new node(m+1, e);
		}
	}
	void up(int left, int right, int v){
		if (left>right)return;
		propagate();
		if (s==left && e==right)lazy+=v;
		else{
			if (right<=m)l->up(left, right, v);
			else if (left>m)r->up(left, right, v);
			else l->up(left, m, v), r->up(m+1, right, v);
			r->propagate(), l->propagate();
			if (l->val.fi==r->val.fi)val=mp(l->val.fi, l->val.se+r->val.se);
			else val=min(l->val, r->val);
		}
	}
}*st;

void update(int x, int y, int v){
	vector<int> temp;
	temp.pb(graph[x][y]);
	temp.pb(graph[x+1][y]);
	temp.pb(graph[x][y+1]);
	temp.pb(graph[x+1][y+1]);
	sort(temp.begin(), temp.end());
	st->up(temp[0], temp[1]-1, v);
	st->up(temp[2], temp[3]-1, 5*v);
}

void add(int x, int y, int v){
	update(x, y, v);
	update(x-1, y, v);
	update(x, y-1, v);
	update(x-1, y-1, v);
}

void give_initial_chart(int H, int W, vector<int> R, vector<int> C){
	h=H, w=W, n=h*w;
	vect.resize(n);
	graph.resize(h+2, vector<int>(w+2, h*w));
	st = new node(0, n-1);
	for (int i=0; i<n; ++i){
		vect[i]=mp(R[i]+1, C[i]+1);
		graph[R[i]+1][C[i]+1]=i;
	}
	for (int i=0; i<=h; ++i)for (int j=0; j<=W; ++j)update(i, j, 1);
}

int swap_seats(int a, int b){
	add(vect[a].fi, vect[a].se, -1);
	add(vect[b].fi, vect[b].se, -1);
	swap(graph[vect[a].fi][vect[a].se], graph[vect[b].fi][vect[b].se]);
	swap(vect[a], vect[b]);
	add(vect[a].fi, vect[a].se, 1);
	add(vect[b].fi, vect[b].se, 1);
	st->propagate();
	if (st->val.fi==4)return st->val.se;
	return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 6 / 6
• Subtask 3: 20 / 20
• Subtask 4: 6 / 6
• Subtask 5: 33 / 33
• Subtask 6: 30 / 30