#include<bits/stdc++.h>
using namespace std;
const int N = 2e3;
const int inf = 1e9;
int n,m,mx = -1;
int v[N][N];
int v2[N][N];
int pref[N][N];
int suf[N][N];
int sufmx[N][N];
int ans = inf;
bool chk(int x){
bool ok = 0;
int pt = m - 1;
int mx2 = -inf,mn2 = inf;
for(int i = 0;i < n;i++){
while(pt >= 0 && pref[i][pt] < mx - x){
pt--;
}
if(pt != m - 1){
mx2 = max(sufmx[i][pt + 1],mx2);
mn2 = min(suf[i][pt + 1], mn2);
}
}
if(mx2 - mn2 <= x){
ok = 1;
}
return ok;
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin>>n>>m;
for(int i = 0;i < n;i++){
for(int j = 0;j < m;j++){
cin>>v[i][j];
mx = max(mx,v[i][j]);
}
}
ans = mx;
for(int k = 0;k < 2;k++){
for(int i = 0;i < n;i++){
for(int j = 0;j < m;j++){
pref[i][j] = min((j == 0?inf:pref[i][j - 1]),v[i][j]);
}
}
for(int i = 0;i < n;i++){
for(int j = m - 1;j >= 0;j--){
suf[i][j] = min((j == m - 1?inf:suf[i][j + 1]),v[i][j]);
sufmx[i][j] = max((j == m - 1?0:sufmx[i][j + 1]),v[i][j]);
}
}
int l = 0,r = ans;
while(l != r){
int mij = (l + r)/2;
if(chk(mij)){
r = mij;
}else l = mij + 1;
}
ans = min(ans,l);
for(int i = 0;i < n;i++){
for(int j = 0;j < m;j++){
v2[j][n - i - 1] = v[i][j];
}
}
swap(n,m);
for(int i = 0;i < n;i++){
for(int j = 0;j < m;j++){
v[i][j] = v2[i][j];
}
}
}
cout<<ans<<'\n';
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
604 KB |
Output is correct |
2 |
Correct |
0 ms |
604 KB |
Output is correct |
3 |
Correct |
0 ms |
604 KB |
Output is correct |
4 |
Incorrect |
0 ms |
604 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
604 KB |
Output is correct |
2 |
Correct |
0 ms |
604 KB |
Output is correct |
3 |
Correct |
0 ms |
604 KB |
Output is correct |
4 |
Incorrect |
0 ms |
604 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
604 KB |
Output is correct |
2 |
Correct |
0 ms |
604 KB |
Output is correct |
3 |
Correct |
0 ms |
604 KB |
Output is correct |
4 |
Incorrect |
0 ms |
604 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |