问题描述：给定n个石子，其重量为a1,a2...,an,要求将其划分为m堆，每一份划分的费用定义为这堆石头中最大重量与最小重量的差的平方。总划分费用等于各堆费用之和。

输入：n m 及a1,a2...,an

输出：sum

问题描述：给定n个石子，其重量为a1,a2...,an,要求将其划分为m堆，每一份划分的费用定义为这堆石头中最大重量与最小重量的差的平方。总划分费用等于各堆费用之和。

输入：n m 及a1,a2...,an

输出：sum

-Descr iption of the problem: Given n-stones, the weight of a1, a2 ..., an, requests that it be divided into m heap, the cost of each division is defined as the weight of this pile of stone, the largest and the smallest weight of the square of the difference . Divide the total cost is equal to the cost of each stack and the. Input: nm and a1, a2 ..., an output: sum descr iption of the problem: Given n-stones, the weight of a1, a2 ..., an, requests that it be divided into m piles, each division of the cost of is defined as the weight of this pile of stone, the largest and the smallest weight of the square of the difference. Divide the total cost is equal to the cost of each stack and the. Input: nm and a1, a2 ..., an output: sum