C++ :

#include <stdio.h>  
#include <string.h>  
#define MAX 10000000  
#define MIN -10000000  
int line[200],n,m,Min,Max,sum[200];  
int f[200][20];//f[i][j]=第1-i个数分成j份，结果最大值  
int g[200][20];//g[i][j]=第1-i个数分成j份，结果最小值  
int min(int a,int b)  
{  
    if(a>b)  
        return b;  
    return a;  
}  
int max(int a,int b)  
{  
    if(a>b)  
        return a;  
    return b;  
}  
void dp(int a[])  
{  
    int i,j,k;  
    for(i=1;i<=n;i++)  
        sum[i]=sum[i-1]+a[i];  
    for(i=0;i<=n;i++)  
        for(j=0;j<=m;j++)  
        {  
            f[i][j]=0;  
            g[i][j]=-1u>>1;  
        }  
    for(i=1;i<=n;i++)  
    {  
        f[i][1]=g[i][1]=(sum[i]%10+10)%10;  
    }  
    f[0][0]=1;  
    g[0][0]=1;  
    for(j=2;j<=m;j++)  
    {  
        for(i=j;i<=n;i++)  
        {  
            for(k=j-1;k<i;k++)  
            {  
                {  
                    f[i][j]=max(f[i][j],f[k][j-1]*(((sum[i]-sum[k])%10+10)%10));  
                    g[i][j]=min(g[i][j],g[k][j-1]*(((sum[i]-sum[k])%10+10)%10));  
                }  
            }  
        }  
    }  
    Max=max(Max,f[n][m]);  
    Min=min(Min,g[n][m]);  
}  
int main()  
{  
    //freopen("game.in","r",stdin);
    //freopen("game.out","w",stdout);
    int i,j,k;  
    Max=0;  
    Min=-1u>>1;  
    scanf("%d%d",&n,&m);  
    for(i=1;i<=n;i++)  
    {  
        scanf("%d",&line[i]);  
        line[i+n]=line[i];  
    }  
    for(i=0;i<n;i++)  
        dp(line+i);  
    printf("%d\n%d\n",Min,Max);  
    return 0;  
}  

Pascal :

var
    a,atmp:array[0..50] of longint;
    f:array[0..9,0..50] of longint;
    n,m,i:longint;
function g(a,b:longint):longint;
var
    i:longint;
begin
    g:=0;
    for i:=a to b do
        if atmp[i]>0 then g:=g+atmp[i]
        else g:=g+atmp[i];
    g:=(g+100000) mod 10;
end;
procedure question_min;
var
    t,i,j,k,tmp,min:longint;
begin
    min:=maxlongint;
    for t:=1 to n do
    begin
        for i:=1 to n do atmp[i]:=a[(i+t-1) mod n];
        atmp[n-t+1]:=a[n];f[0,1]:=atmp[1];
        for i:=1 to n do f[0,i]:=g(1,i);
        for i:=1 to m-1 do
            for j:=i+1 to n do
            begin
                f[i,j]:=maxlongint;
                for k:=i to j-1 do
                begin
                    tmp:=g(k+1,j);
                    if f[i,j]>tmp*f[i-1,k] then f[i,j]:=tmp*f[i-1,k];
                end;
            end;
        if f[m-1,n]<min then min:=f[m-1,n];
    end;
    writeln(min);
end;
procedure question_max;
var
    t,i,j,k,tmp,max:longint;
begin
    max:=0;
    for t:=1 to n do
    begin
        for i:=1 to n do atmp[i]:=a[(i+t-1) mod n];
        atmp[n-t+1]:=a[n];f[0,1]:=atmp[1];
        for i:=1 to n do f[0,i]:=g(1,i);
        for i:=1 to m-1 do
            for j:=i+1 to n do
            begin
                f[i,j]:=0;
                for k:=i to j-1 do
                begin
                    tmp:=g(k+1,j);
                    if f[i,j]<tmp*f[i-1,k] then f[i,j]:=tmp*f[i-1,k];
                end;
            end;
        if f[m-1,n]>max then max:=f[m-1,n];
    end;
    writeln(max);
end;
begin
{assign(input,'game.in');reset(input);
 assign(output,'game.out');rewrite(output);}
    readln(n,m);
    for i:=1 to n do readln(a[i]);
    question_min;
    question_max;
{close(input);
 close(output);}
end.