#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) begin(a),end(a)
const int N = (int)2e3+2;
bitset<N> dp[N];
int n, m, a[N][N], b[N][N], c[N][N];
void Rotate(){
for(int i = 0; i < n; i++)
for(int j = 0; j < m; j++)
c[i][j] = b[i][j];
for(int i = 0; i < n; i++)
for(int j = 0; j < m; j++)
b[j][i] = c[i][m-j-1];
swap(n,m);
}
bool calc(){
for(int k : {1,2}){
int bst=-1,bst2,lst,sum;
for(int i = 0; i < n; i++){
bst2=-1; lst=0; sum = 0;
for(int j = m-1; j>=0; j--){
if(b[i][j]==k){ lst=j+1; break; }
}
for(int j = 0; j <= m; j++){
if(sum==j){
if(!i) dp[i][j]=(j>=lst and j!=m);
else if(bst!=-1) dp[i][j]=(j>=lst and bst<=j);
if(dp[i][j] and bst2==-1) bst2=j;
}
else dp[i][j]=0;
sum+=(!b[i][j] or b[i][j]==k);
}
bst=bst2;
}
bool ok = 0;
for(int i = 1; i <= m; i++) ok|=dp[n-1][i];
if(ok) return 1;
}
return 0;
}
int mn = (int)1e9, mx = 0;
bool chk(int R){
memset(b,0,sizeof(b));
for(int i = 0; i < n; i++){
for(int j = 0; j < m; j++){
if(a[i][j]>mn+R) b[i][j]=2;
if(a[i][j]<mx-R){
if(b[i][j]==2) return 0;
b[i][j] = 1;
}
}
}
bool ok = 0;
for(int i = 0; i < 4 and !ok; i++)
ok|=calc(), Rotate();
return ok;
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(0);
cin >> n >> m;
for(int i = 0; i < n; i++)
for(int j = 0; j < m; j++)
cin >> a[i][j],mn=min(mn,a[i][j]),mx=max(mx,a[i][j]);
int l = 0, r = mx-mn;
while(l<r){
int mid = (l+r)/2;
if(chk(mid)) r=mid;
else l=mid+1;
}
cout << l << "\n";
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
6 ms |
20816 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
6 ms |
20816 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
6 ms |
20816 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
