java - topN排序问题求解。

Question

有个字符串数组，string[] str = {A,B,C,D,E,F,G,H};，数组分别对应一个整数数组，int[] a = {3,2,6,4,8,9,1,23};，类似于这样，对整数数组中的数从大到小排序，然后将整数数组对应的字符串数组按序输出，求解java代码的实现方式。

Answer 1

You define a Holder class to save the character-number mapping, then sort all Holders according to the numbers in the Holders from large to small, and finally output the characters of each Holder in order.

<code>import java.util.Arrays;

public class Test {

    static class Holder implements Comparable<Holder> {

        public int num;
        public String str;

        public Holder(String str, int num) {
            this.str = str;
            this.num = num;
        }

        @Override
        public int compareTo(Holder that) {
            return that.num - this.num; // 逆序排序
        }

    }

    public static void test(String[] strs, int[] nums) {
        if (strs.length != nums.length) {
            return;
        }

        Holder[] holders = new Holder[strs.length];
        for (int i = 0; i < strs.length; i++) {
            holders[i] = new Holder(strs[i], nums[i]);
        }

        Arrays.sort(holders);

        for (Holder holder : holders) {
            System.out.print(holder.str + " ");
        }
        System.out.println();
    }

    public static void main(String[] args) throws Exception {
        String[] strs = {"A", "B", "C", "D", "E", "F", "G", "H"};
        int[] a = {3, 2, 6, 4, 8, 9, 1, 23};

        test(strs, a);
    }
}
</code>

Run results: