hihoCoder 1595 : Numbers

Description

You are given n constant integers c[1], c[2], ..., c[n] and an integer k. You are to assign values to 2k integer variables, x[1], x[2], ..., x[k], y[1], y[2], ..., y[k], such that,

(1) For each 1 ≤ i ≤ k, x[i] ≤ y[i] holds,

(2) For each 1 ≤ i ≤ n, exists at least one such j (1 ≤ j ≤ k) that x[j] ≤ c[i] ≤ y[j].

Please find the minimum value of S=(y[1]+y[2]+...+y[k])-(x[1]+x[2]+...+x[k]).

Input

First line contains two integers n, k. (1 ≤ n, k ≤ 100000)

Following n lines contain integers c[1], c[2], ..., c[n]. (-1000000000 ≤ c[i] ≤ 1000000000)

Output

Output the minimum value of integer S.

Sample Hint

x[1]=-5, y[1]=4,

x[2]=10, y[2]=10.

http://hihocoder.com/contest/challenge31/solution/1201723

比赛中唯一让人感到美好的题目

按从小到大排序

定义一个区间大小为最大减最小

那么题目就是要把n个数分为k个区间，使和最小

贪心，一开始只分出1～n一个区间，后面将k-1个相邻差最大的值减去

 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 using namespace std;
 int n,k,c[],d[];
 long long ans;
 bool cmp(int a,int b)
 {
     return a>b;
 }
 int main()
 {int i;
     cin>>n>>k;
     for (i=;i<=n;i++)
     {
         scanf("%d",&c[i]);
     }
     sort(c+,c+n+);
     ans=c[n]-c[];
     for (i=;i<n;i++)
     d[i]=c[i+]-c[i];
     sort(d+,d+n,cmp);
     for (i=;i<=k-;i++)
     {
         ans-=d[i];
     }
     cout<<ans;
 }