不知为何WA 0 分
#include<iostream>
#include<cstdio>
#include<cmath>
using namespace std;
int n,m,kkk,ans=1e8,f[1001][1001][10],f1[1000][1001][10],a[1001][1001];
int check(int xx1,int yy1,int xx2,int yy2)
{
int k=log2(xx2-xx1+1);
int ans1=max(f[xx1][yy1][k],f[xx2-(1<<k)+1][yy1][k]);
int ans2=max(f[xx1][yy2-(1<<k)+1][k],f[xx2-(1<<k)+1][yy2-(1<<k)+1][k]);
return max(ans2,ans1);
}
int check1(int xx1,int yy1,int xx2,int yy2)
{
int k=log2(xx2-xx1+1);
int ans1=min(f1[xx1][yy1][k],f1[xx2-(1<<k)+1][yy1][k]);
int ans2=min(f1[xx1][yy2-(1<<k)+1][k],f1[xx2-(1<<k)+1][yy2-(1<<k)+1][k]);
return min(ans2,ans1);
}
int main()
{
cin>>n>>m>>kkk;
for(int i=1; i<=n; i++)
for(int j=1; j<=m; j++)
scanf("%lld",&a[i][j]);
for(int k=0; k<=log2(100); k++)
for(int i=1; i+(1<<k)-1<=n; i++)
for(int j=1; j+(1<<k)-1<=m; j++)
{
if(k==0)
{
f[i][j][k]=a[i][j];
f1[i][j][k]=a[i][j];
}
else
{
f[i][j][k]=max(f[i][j][k-1],f[i+(1<<(k-1))][j][k-1]);
f1[i][j][k]=min(f1[i][j][k-1],f1[i+(1<<(k-1))][j][k-1]);
f[i][j][k]=max(f[i][j][k-1],f[i][j+(1<<(k-1))][k-1]);
f1[i][j][k]=min(f1[i][j][k-1],f1[i][j+(1<<(k-1))][k-1]);
}
}
for(int i=1; i+kkk-1<=n; i++)
for(int j=1; j+kkk-1<=m; j++)
ans=min(ans,check(i,j,i+kkk-1,j+kkk-1)-check1(i,j,i+kkk-1,j+kkk-1));
cout<<ans;
return 0;
}