Submission #1158639

#TimeUsernameProblemLanguageResultExecution timeMemory
1158639alexander707070Furniture (JOI20_furniture)C++20
100 / 100
612 ms171712 KiB
#include<bits/stdc++.h>
#define MAXN 1007
using namespace std;

int n,m,x,y,qs;
int t[MAXN][MAXN];
bool vis[MAXN][MAXN];

int parent[MAXN*MAXN],depth[MAXN*MAXN];
bool ans[MAXN*MAXN];

pair<int,int> jump[MAXN*MAXN][20];


int val(int x){
	return t[(x-1)/m+1][(x-1)%m+1];
}

int coor(int x,int y){
	return (x-1)*m+y;
}

pair<int,int> lca(int x,int y){
	int l=qs+1,r=qs+1;
	bool sw=false;

	if(depth[x]<depth[y]){
		swap(x,y);
		sw=true;
	}

	for(int i=19;i>=0;i--){
		if((1<<i)<=depth[x]-depth[y]){
			l=min(l,jump[x][i].second);
			x=jump[x][i].first;
		}
	}

	if(x==y){
		if(sw)swap(l,r);
		return {l,r};
	}

	for(int i=19;i>=0;i--){
		if((1<<i)<=depth[x] and jump[x][i].first!=jump[y][i].first){
			l=min(l,jump[x][i].second);
			r=min(r,jump[y][i].second);

			x=jump[x][i].first;
			y=jump[y][i].first;
		}
	}

	l=min(l,jump[x][0].second);
	r=min(r,jump[y][0].second);

	if(sw)swap(l,r);
	return {l,r};
}

bool bigger(int a,int b){
	if(val(a)==0)a=parent[a];
	if(val(b)==0)b=parent[b];

	if(a==b)return true;

	auto p=lca(a,b);
	
	return p.first >= p.second;
}

void recur(int x){
	while(x!=1){
		ans[val(x)]=false;
		x=parent[x];
	}
}

void add(int p,int q){
	parent[q]=p; depth[q]=depth[p]+1;

	jump[q][0]={p,val(q)};

	for(int s=1;s<20 and (1<<s)<=depth[q];s++){
		jump[q][s].first=jump[jump[q][s-1].first][s-1].first;
		jump[q][s].second = min( jump[q][s-1].second , jump[jump[q][s-1].first][s-1].second );
	}
}

int main(){

	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);

	cin>>n>>m;

	for(int i=1;i<=n;i++){
		for(int f=1;f<=m;f++){
			cin>>t[i][f];
			t[i][f]=-t[i][f];
		}
	}

	cin>>qs;
	for(int i=1;i<=qs;i++){
		cin>>x>>y;
		t[x][y]=i;
		ans[i]=true;
	}

	for(int i=1;i<=n;i++){
		for(int f=1;f<=m;f++){
			
			if(i==1 and f==1){
				parent[1]=1;
				continue;
			}
			
			if(t[i][f]==-1)continue;

			if((i==1 or parent[coor(i-1,f)]==0) and (f==1 or parent[coor(i,f-1)]==0))continue;

			if(i==1 or parent[coor(i-1,f)]==0){
				if(t[i][f-1]==0)add( parent[coor(i,f-1)] , coor(i,f) );
				else add( coor(i,f-1) , coor(i,f) );
				continue;
			}

			if(f==1 or parent[coor(i,f-1)]==0){
				if(t[i-1][f]==0)add( parent[coor(i-1,f)] , coor(i,f) );
				else add( coor(i-1,f) , coor(i,f) );
				continue;
			}

			if(bigger( coor(i-1,f) , coor(i,f-1) )){
				if(t[i-1][f]==0)add( parent[coor(i-1,f)] , coor(i,f) );
				else add( coor(i-1,f) , coor(i,f) );
			}else{
				if(t[i][f-1]==0)add( parent[coor(i,f-1)] , coor(i,f) );
				else add( coor(i,f-1) , coor(i,f) );
			}
		}
	}

	recur(coor(n,m));

	for(int i=1;i<=qs;i++){
		cout<<ans[i]<<"\n";
	}

	return 0;
}
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