如何构建从二维int数组ArrayList的？ [英] How to construct ArrayList from 2D int array?

问题描述

我有一个二维int数组，我想删除重复的行例如：

I have a 2D int array, i want to remove duplicate rows for example

30,40,50

50,30,40

30,40,50

在上面的例子中第2和放大器;第三行是重复第一排的。

in above example 2nd & 3rd row is duplicate of 1st row.

我知道的ArrayList 可以动态增加和水槽这是这个概念有用的，但我们如何转换 INT [] [] 到的ArrayList 。

I know ArrayList can dynamically grow and sink which is useful class for this concept but how we convert int[][] into ArrayList.

推荐答案

首先，你应该创建一个类来保存你的数据其覆盖公共布尔等于（obj对象）和公众诠释哈希code（）来表示数据的平等。

First, you should create a Class to hold you data which override public boolean equals(Object obj) and public int hashCode() to indicate equality of the data.

public class Row {

    private int[] ints;

    public Row(int[] ints) {
        this.ints = ints.clone();
        Arrays.sort(this.ints);
    }

    @Override
    public int hashCode() {
        return Arrays.hashCode(ints);
    }

    @Override
    public boolean equals(Object obj) {

        if(obj instanceof Row) {
            Row another = (Row) obj;
            int[] original = Arrays.copyOf(another.ints, another.ints.length);
            return Arrays.equals(ints, original);
        } else {
            return false;
        }
    }

    @Override
    public String toString() {
        return Arrays.toString(ints);
    }

}

测试用例

public class Test {

    public static void main(String[] args) {
        int[][] arrays = new int[][]{{30,40,50}, {50,30,40}, {30,40,50}, {10, 20, 30}};
        Set<Row> rows = new HashSet<Row>();
        for(int[] a: arrays) {
            rows.add(new Row(a));
        }
        for(Row row: rows) {
            System.out.println(row);
        }
    }
}

输出

[10, 20, 30]
[30, 40, 50]

这篇关于如何构建从二维int数组ArrayList的？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！