如何比较 (x,y) 点进行排序，其中 x 总是第一个

Question

我正在使用 Java 比较器将位置对象与点 (x,y) 进行比较。

我需要能够比较两个点以检索正整数或负整数，这将允许我对 (x,y) 点进行排序，其中首先对 x 值进行排序，然后对 y 值进行排序。（如果这是有道理的......）例如，这个：

(3,4) (2,5) (1,1) (1,3) (3,3)

变成这样：

(1,1) (1,3) (2,5) (3,3) (3,4)

我想过的一种方法基本上是通过将 x 值乘以一个很大的数字（如 1000）来赋予 x 值较大的优先级。像这样：比较 (3,3) 和 (1,1)：

int x_multiplier = 1000;
int value1 = (p1.x * x_multiplier ) + p1.y; // = 3 * 1000 + 3 = 3003
int value2 = (p2.x * x_multiplier ) + p2.y; // = 1 * 1000 + 1 = 1001
return value1-value2; // = 2002. Value1 is greater, thus p1 be later in list.

这行得通，但问题是如果 Y 值应该等于或大于 x_multiplier，那么它就会失效（因为 y 值现在等于 1 x -价值...再一次，如果这有意义的话。）

// Comparing p1 = (2,0) & p2 = (1,18)
int x_multiplier = 10;
int value1 = (p1.x * x_multiplier ) + p1.y; // = 2 * 10 + 0  = 20
int value2 = (p2.x * x_multiplier ) + p2.y; // = 1 * 10 + 18 = 28
return value1-value2; // = -8, value2 is greater, and thus p2 will be later in the list. However, we know by looking at the points that p2 should come first.

我什至不知道如何搜索这个，所以即使有答案我也找不到。

Answer 1

import java.util.*;

class Tuple {
    public int x, y;

    Tuple(int x, int y) {
        this.x = x;
        this.y = y;
    }

    @Override
    public String toString() {
        return "(" + x + ", " + y + ") ";
    }
}

public class coord {
    public static void main(String[] args) {
        LinkedList<Tuple> list = new LinkedList<Tuple>();
        list.add(new Tuple(3,4));
        list.add(new Tuple(2,5));
        list.add(new Tuple(1,1));
        list.add(new Tuple(1,3));
        list.add(new Tuple(3,3));
        for (Tuple t: list) {
            System.out.print(t);
        }
        Collections.sort(list, (Tuple t1, Tuple t2) -> {
            int result = Integer.compare(t1.x, t2.x);
            if (result == 0 ) result = Integer.compare(t1.y, t2.y);
            return result;
        });
        System.out.println("Sorted List: ");
        for (Tuple t: list) {
            System.out.print(t);
        }
    }
}

如何比较 (x,y) 点进行排序，其中 x 总是第一个

How to compare (x,y) points for sorting, where x is always first

java

sorting

2d

points

comparator