6、贪心 &绝对值不等式

AcWing 104. 货仓选址

import java.util.*;
import java.util.concurrent.LinkedTransferQueue;

//ACWing
public class Main {
    public static void main(String[] args) {
        Main main = new Main();
        main.init();

    }
    int N=100010;
    int a[];
    void init() {
        Scanner sc = new Scanner(System.in);
        int n=sc.nextInt();
        a=new int[n];
        for (int i = 0; i < n; i++) {
            a[i]=sc.nextInt();
        }
        Arrays.sort(a);
        long sum=0;
        if(n%2==0){
            int start=n/2-1;
            int end=n/2;
            int pos=(a[start]+a[end])/2;
            for (int i = 0; i < n; i++) {
                sum+=Math.abs(pos-a[i]);
            }
        }else{
            int pos=a[n/2];
            for (int i = 0; i < n; i++) {
                sum+=Math.abs(pos-a[i]);
            }
        }
        System.out.println(sum);
    }
}