Submission #286018

#	Time	Username	Problem	Language	Result	Execution time	Memory
286018		YJU	The Kingdom of JOIOI (JOI17_joioi)	C++14	0 / 100	1 ms	384 KiB

joioi

#include<bits/stdc++.h>
#pragma GCC optimize("unroll-loops,no-stack-protector")
using namespace std;
typedef int ll;
typedef long double ld;
typedef pair<ll,ll> pll;
const ll MOD=1e9+7;
const ll MOD2=998244353;
const ll N=2e3+5;
const ld pi=3.14159265359;
const ll INF=(1LL<<31);
#define SQ(i) ((i)*(i))
#define REP(i,n) for(ll i=0;i<n;i++)
#define REP1(i,n) for(ll i=1;i<=n;i++)
#define pb push_back
#define mp make_pair
#define X first
#define Y second
#define setp setprecision
#define lwb lower_bound
#define SZ(_a) (ll)_a.size()

priority_queue<pair<ll,pll> > pq;
ll n,m,u[N][N],vis[N][N],dg[N][N],x,y;
ll dx[4]={-1,0,1,0},dy[4]={0,1,0,-1};
long long ans;


bool BFS(ll sx,ll sy,ll ty,ll D,ll k){
	REP(i,n+2)REP(j,m+2){
		dg[i][j]=(i==sx?1:0)+(j==sy?1:0);
		vis[i][j]=0;
	}
	ll mn=u[sx][sy],mx=u[sx][sy];
	pq.push(mp(mx,mp(sx,sy)));
	while(SZ(pq)){
		auto tmp=pq.top();pq.pop();
		if(max(mx,tmp.X)-min(mn,tmp.X)>k)continue;
		x=tmp.Y.X;y=tmp.Y.Y;
		vis[x][y]=1;mn=min(mn,tmp.X);mx=max(mx,tmp.X);
		REP(i,4)if((1LL<<i)&D){
			ll nx=x+dx[i],ny=y+dy[i];
			++dg[nx][ny];
			if(dg[nx][ny]==2){
				pq.push(mp(u[nx][ny],mp(nx,ny)));
			}
		}
	}
	mn=INF;mx=-INF;
	REP1(i,n)REP1(j,m){
		if(!vis[i][j])mn=min(mn,u[i][j]),mx=max(mx,u[i][j]);
	}
	return (mx-mn>k?0:1);
}

bool ok(ll k){
	if(BFS(1,1,0,6,k)||BFS(1,m,0,12,k)||BFS(n,1,0,3,k)||BFS(n,m,0,9,k))return 1;
	return 0;
}

int main(){
	ios_base::sync_with_stdio(0);cin.tie(0);
	cin>>n>>m;
	REP1(i,n)REP1(j,m)cin>>u[i][j];
	for(int i=30;i>=0;i--){
		if(!ok(ans+(1LL<<i)))ans+=(1LL<<i);
	}
	cout<<ans+1<<"\n";
	return 0;
}

Compilation message (stderr)

joioi.cpp: In function 'bool BFS(ll, ll, ll, ll, ll)':
joioi.cpp:49:12: warning: integer overflow in expression of type 'int' results in '-2147483648' [-Woverflow]
   49 |  mn=INF;mx=-INF;
      |            ^~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 45
• Subtask 3: 0 / 40