hdu oj 2020 绝对值排序

map的应用

输入n(n<=100)个整数，按照绝对值从大到小排序后输出。题目保证对于每一个测试实例，所有的数的绝对值都不相等。

import java.text.DecimalFormat;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        @SuppressWarnings("resource")
        Scanner in = new Scanner(System.in);
        DecimalFormat df = new DecimalFormat("#0.00");
        while (in.hasNextInt()) {
            int n = in.nextInt();
            if (n == 0)
                return;
            int[] arr = new int[n];
            for (int i = 0; i < n; ++i) {
                arr[i] = in.nextInt();
            }
            sortArray(arr);
        }
    }

    private static void sortArray(int[] arr) {
        // TODO Auto-generated method stub
        int[] newArr = new int[arr.length];
        Map<Integer, Integer> map = new HashMap<Integer, Integer>();
        for (int i = 0, len = arr.length; i < len; i++) {
            newArr[i] = Math.abs(arr[i]);
            map.put(newArr[i], arr[i]);
        }
        Arrays.sort(newArr);
        System.out.print(map.get(newArr[newArr.length - 1]));
        for (int i = newArr.length - 2; i >= 0; --i) {
            System.out.print(" " + map.get(newArr[i]));
        }
        System.out.println();
    }
}