Submission #202327

#	Time	Username	Problem	Language	Result	Execution time	Memory
202327		errorgorn	Seats (IOI18_seats)	C++14	25 / 100	1836 ms	64960 KiB

seats

#include "seats.h"
#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> ii;
 
 
struct node{
	int seg[2005]; ///at least double the original array
	int padding=1005;
	
	void update(int i,int j){
		i+=padding;
		seg[i]=j;
		i>>=1;
		while (i){
			seg[i]=max(seg[i<<1],seg[(i<<1)|1]);
			i>>=1;
		}
	}
	int query(int l,int r){ //[l,r], with 0-indexing
		int res=0;
		for (l+=padding,r+=padding+1;l<r;l>>=1,r>>=1){
			if (l&1){
				res=max(res,seg[l]);
				l++;
			}
			if (r&1){
				r--;
				res=max(res,seg[r]);
			}
		}
		return res;
	}

};
 
int h,w;
ii pos[1000005];
 
node hor[1005];
node ver[1005];

 
void give_initial_chart(int H, int W, std::vector<int> R, std::vector<int> C) {
	h=H,w=W;
	for (int x=0;x<h*w;x++){
		pos[x]=ii(R[x],C[x]);
		ver[pos[x].first].update(pos[x].second,x);
		hor[pos[x].second].update(pos[x].first,x);
	}
}
 
int swap_seats(int a, int b) {
	swap(pos[a],pos[b]);
	
	ver[pos[a].first].update(pos[a].second,a);
	hor[pos[a].second].update(pos[a].first,a);
	
	ver[pos[b].first].update(pos[b].second,b);
	hor[pos[b].second].update(pos[b].first,b);
	
	int x1,x2,y1,y2;
	x1=x2=pos[0].first;
	y1=y2=pos[0].second;
	
	int s=1;
	int biggest=0;
	int res=1;
	while (s<h*w){
		int best=1000000000,tmp;
		int dir=-1;
		
		if (0<x1){
			tmp=ver[x1-1].query(y1,y2);
			if (tmp<best){
				best=tmp;
				dir=0;
			}
		}
		if (x2<h-1){
			tmp=ver[x2+1].query(y1,y2);
			if (tmp<best){
				best=tmp;
				dir=1;
			}
		}
		if (0<y1){
			tmp=hor[y1-1].query(x1,x2);
			if (tmp<best){
				best=tmp;
				dir=2;
			}
		}
		if (y2<w-1){
			tmp=hor[y2+1].query(x1,x2);
			if (tmp<best){
				best=tmp;
				dir=3;
			}
		}
		
		if (dir==0){
			x1--;
			s+=y2-y1+1;
		}
		else if (dir==1){
			x2++;
			s+=y2-y1+1;
		}
		else if (dir==2){
			y1--;
			s+=x2-x1+1;
		}
		else{
			y2++;
			s+=x2-x1+1;
		}
		
		biggest=max(biggest,best);
		if (biggest==s-1) res++;
	}
	
	return res;
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 6
• Subtask 3: 20 / 20
• Subtask 4: 0 / 6
• Subtask 5: 0 / 33
• Subtask 6: 0 / 30