每日一练125——Java整数数组合并去重排序(8kyu)

题目

编写一个函数，将两个已排序数组合并为一个数组。数组只包含整数。此外，必须对最终结果进行排序，不得有任何重复。

测试用例

import org.junit.Test;
import static org.junit.Assert.assertArrayEquals;

public class SolutionTest {

    @Test
    public void basicTest() {
        assertArrayEquals(new int[] { 1, 2, 3, 4, 5, 6 }, Kata.mergeArrays(new int[] { 1, 3, 5 }, new int[] { 2, 4, 6 }));
        assertArrayEquals(new int[] { 2, 4, 6, 8 }, Kata.mergeArrays(new int[] { 2, 4, 8 }, new int[] { 2, 4, 6 }));
    }
}

解题

My

import java.util.*;
public class Kata {
    public static int[] mergeArrays(int[] first, int[] second) {
        // 去重
        HashSet hashSet = new HashSet();
        for (int aFirst : first) {
            hashSet.add(aFirst);
        }
        for (int aSecond : second) {
            hashSet.add(aSecond);
        }
        // 利用TreeSet排序
        Set set = new TreeSet(hashSet);
        Integer[] integers = set.toArray(new Integer[]{});

        // 排序去重后的结果数组
        int[] result = new int[integers.length];
        for (int i = 0; i < integers.length; i++) {
            result[i] = integers[i];
        }
        return result;
    }
}

Other

import java.util.stream.*;
public class Kata {
  public static int[] mergeArrays(int[] first, int[] second) {
    return IntStream.concat(IntStream.of(first),IntStream.of(second)).distinct().sorted().toArray();
  }
}

import static java.util.stream.IntStream.*;

public class Kata {

  public static int[] mergeArrays(int[] a, int[] b) {
    return concat(of(a), of(b)).sorted().distinct().toArray();
  }

}

import java.util.*;
public class Kata {
  public static int[] mergeArrays(int[] first, int[] second) {
String str = Arrays.toString(first).replaceAll("[^0-9,-]","") + "," + Arrays.toString(second).replaceAll("[^0-9,-]","");
String[] arr = str.split(",");
int[] arrint = new int[arr.length];
for (int i =0; i

后记

other里我挑了简单，还有比我还要长的，看起来IntStream的方法真好用。