1197：山区建小学

 

#include<cstdio>
#include<cmath>
#include<iostream>
using namespace std; 
int a[505][505],c[505][505],f[505][505];
int main()
{
    int m,n;
    scanf("%d%d",&m,&n);
    for(int i = 1; i < m; ++i)
        scanf("%d",&a[i][i+1]);
    for(int i = 1; i <= m; ++i) 
    {
        for(int  j = i+1; j <= m; ++j)
        {
            a[i][j] = a[j-1][j] + a[i][j-1];
            a[j][i] = a[i][j];
        }
    } 
    int mid;
    for(int i = 1; i <= m; ++i)
    {
        for(int j = i+1; j <= m; ++j)
        {
            mid=(i+j)/2; 
            c[i][j] = 0; 
            for(int k = i; k <= j; ++k)
                c[i][j] += a[k][mid]; 
        }
    } 
    for(int i = 1; i <= m; ++i)
        f[i][1] = c[1][i];
    int s = 0x7fffffff; 
    for(int i = 1; i <= m; ++i)
    {
        for(int j = 2; j <= n; ++j)
        {
            f[i][j] = s;
            for(int k  = j-1; k <= i; ++k)
                f[i][j] = min(f[i][j],f[k][j-1]+c[k+1][i]);
        }
     } 
    printf("%d",f[m][n]);
    return 0;
}