#include<bits/stdc++.h>
using namespace std;
const long long mod=998244353;
int xx[]={1,-1,0,0},yy[]={0,0,1,-1};
long long n,m,a[2050][2050],on[2050],of[2050],ans=1e18;
multiset<pair<long long,pair<int,int> > >ms;
multiset<long long>s,s1;
bool vis[2050][2050];
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
//freopen(".in","r",stdin);
//freopen(".out","w",stdout);
cin>>n>>m;
for(int i=0;i<n;i++)
{
for(int j=0;j<m;j++)
{
cin>>a[i][j];
if(i==0||j==0||i==n-1||j==m-1)ms.insert({a[i][j],{i,j}});
s.insert(a[i][j]);
}
}
pair<long long,pair<int,int> >z=*--ms.end();
s.erase(s.lower_bound(z.first));
ans=min(ans,*--s.end()-*s.begin());
s1.insert(z.first);
ms.clear();
int x=z.second.first,y=z.second.second;
vis[x][y]=1;
on[x]=1,of[y]=1;
for(int i=0;i<4;i++)
{
int tx=x+xx[i],ty=y+yy[i];
if(0<=tx&&tx<n&&0<=ty&&ty<m)ms.insert({a[tx][ty],{tx,ty}});
}
while(s.size()>1)
{
pair<long long,pair<int,int> >z=*--ms.end();
ms.erase(--ms.end());
long long val=z.first,x=z.second.first,y=z.second.second;
if(vis[x][y])continue;
if(on[x]&&vis[x][y-1]==0&&vis[x][y+1]==0)continue;
if(of[y]&&vis[x-1][y]==0&&vis[x+1][y]==0)continue;
vis[x][y]=1;
s.erase(s.lower_bound(val));
s1.insert(val);
long long dif=max(*--s1.end()-*s1.begin(),*--s.end()-*s.begin());
ans=min(ans,dif);
on[x]=1,of[y]=1;
for(int i=0;i<4;i++)
{
int tx=x+xx[i],ty=y+yy[i];
if(vis[tx][ty])continue;
if(0<=tx&&tx<n&&0<=ty&&ty<m)
{
if(i<2)
{
if(on[tx]==0)ms.insert({a[tx][ty],{tx,ty}});
else if(vis[tx][ty-1]||vis[tx][ty+1])ms.insert({a[tx][ty],{tx,ty}});
}
if(2<=i)
{
if(of[ty]==0)ms.insert({a[tx][ty],{tx,ty}});
else if(vis[tx-1][ty]||vis[tx+1][ty])ms.insert({a[tx][ty],{tx,ty}});
}
}
}
}
cout<<ans<<endl;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
380 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
380 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
380 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
