#include
     
      using namespace std;const int A=1050;const int N=105;int a,b,n;int g[A][A],q[A][N],Q[A][N];int head[A],tail[A];int Head[A],Tail[A];inline int read(){    int x=0,f=1;char ch=getchar();    while(!isdigit(ch)){
   if(ch=='-')f=-1;ch=getchar();}    while(isdigit(ch)){x=(x<<1)+(x<<3)+(ch^48);ch=getchar();}    return x*f;}int main(){    a=read(),b=read(),n=read();    for(register int i=1;i<=a;i++)    for(register int j=1;j<=b;j++) g[i][j]=read();        for(register int j=1;j<=b;j++){       head[j]=tail[j]=1;       Head[j]=Tail[j]=1;       for(register int i=1;i<=n-1;i++){           while(head[j]<=tail[j]&&g[i][j]<=g[q[j][tail[j]]][j]) tail[j]--;           q[j][++tail[j]]=i;           while(Head[j]<=Tail[j]&&g[i][j]>=g[Q[j][Tail[j]]][j]) Tail[j]--;           Q[j][++Tail[j]]=i;       }    }    int ans=0x3f3f3f3f;    for(register int i=n;i<=a;i++){        for(register int j=1;j<=b;j++){            while(head[j]<=tail[j]&&q[j][head[j]]
      
       =g[Q[j][Tail[j]]][j]) Tail[j]--;            Q[j][++Tail[j]]=i;        }        for(register int j=n;j<=b;j++){            int mi=0x3f3f3f3f,mx=-0x3f3f3f3f;            for(register int k=j-n+1;k<=j;k++){                mi=min(mi,g[q[k][head[k]]][k]);                mx=max(mx,g[Q[k][Head[k]]][k]);            }            ans=min(ans,mx-mi);        }    }    printf("%d\n",ans);return 0;}
      
     

二维单调队列