题目

参考

import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.Scanner;
 
 
public class Main {
    
    public static void main(String[] args) {
        
        Scanner in = new Scanner(System.in);
        String input = in.nextLine();
        String[] numStrs = input.split(" ");
 
        int[] nums = new int[numStrs.length];
        for (int i = 0; i < numStrs.length; i++) {
            nums[i] = Integer.parseInt(numStrs[i]);
        }
       
        int nodeNum = numStrs.length / 2;
        Node[] nodes = new Node[nodeNum];
        for (int i = 0; i < nodeNum; i++) {
            nodes[i] = new Node(nums[2 * i], nums[2 * i + 1]);
        }
 
        Node lastDirect = null;
        Node last = nodes[0];
        List<Node> res = new ArrayList<>();
       
        res.add(nodes[0]);
        for (int i = 1; i < nodes.length; i++) {
          
            Node newDirect = new Node(nodes[i].i - last.i, nodes[i].j - last.j);
           
            if (lastDirect == null) {
                lastDirect = newDirect;
            } else {
               
                if (!lastDirect.equals(newDirect)) {
                    res.add(last);
                    lastDirect = newDirect;
                }
            }
            
            last = nodes[i];
        }
        res.add(last);
 
 
        
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < res.size(); i++) {
            sb.append(res.get(i).i).append(" ");
            sb.append(res.get(i).j).append(" ");
        }
        System.out.println(sb.substring(0, sb.length() - 1));
    }
 
    static class Node {
        int i;
        int j;
 
        public Node(int i, int j) {
            this.i = i;
            this.j = j;
        }
 
        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;
            Node node = (Node) o;
            return i == node.i && j == node.j;
        }
 
        @Override
        public int hashCode() {
            return Objects.hash(i, j);
        }
    }
}

https://blog.csdn.net/weixin_52908342/article/details/135581525