Question

我是Java新手，我正在进行数组排序问题，我遇到了这个问题的困难。搜索了simmular或重复的帖子，但似乎没有找到任何。

问题是“找到数组中最相同的相邻元素并将它们写入新数组”。

我的问题是。 如何将来自另一个数组的大多数相邻元素存储在数组中？

这是我到目前为止所做的工作。

int[] arr= {2, 1, 1, 3, 3, 2, 2, 2, 2, 1 ,1}; //test array

int counter=0;
int i = 0;
int length = arr.length;
int[] resultArr=new int[length];



for (i=1; i<length; i++)

    {
   if (arr[i-1]==arr[i])
    {
     counter++;      // Counter to represent maximal adjacent occurred elem.
     resultArr[i] = arr[i]  //Writing elements in result array
    }





} 
 System.out.println(counter);  
 System.out.println(resultArr);

 Input: It is the test array "arr"

 Output 1 : Shoud be 4 representing the maximum of same adjacent elements ( i.e the 2's in the array )
 Output 2 : Must be an array that contains the 4 elements of the array ({2, 2, 2 ,2} )

我的输出是（直接来自控制台）

1
[I @ 6d06d69c

Answer 1

你在代码中犯了两个错误，首先你对输入数组i和结果数组arr使用相同的索引resultArr，你应该使用另一个错误resultArr喜欢这个

int resultArrIndex = 0;
for (i=1; i<length; i++)
{
  if (arr[i-1]==arr[i])
  {
    counter++;      // Counter to represent maximal adjacent occurred elem.
    resultArr[resultArrIndex] = arr[i]  //Writing elements in result array
    resultArrIndex++;
  }
}

其次，这不是打印数组的方法，要么像这样在for循环中执行

for (int i = 0; i < resultArr.length; i++) {
  System.out.println(resultArr[i]);  // will print each in a line
}

或者像这样

System.out.println(Arrays.toString(resultArr));  // Print all in one line

Answer 2

Break the problem down, first a method to determine when runs of adjacent values stop;

private static int runsTo(int[] vals, int index) {
    for (int i = index; i < vals.length - 1; i++) {
        if (vals[i] != vals[i + 1]) {
            return i;
        }
    }
    return vals.length;
}

Then we can use that with Arrays.toString(int[]) ¹以及Arrays.copyOfRange(int[], int, int)喜欢

int[] arr = { 2, 1, 1, 3, 3, 2, 2, 2, 2, 1, 1 };
int index = 0, count = 0;
for (int i = 0; i < arr.length; i++) {
    int r = runsTo(arr, i);
    int c = r - i + 1;
    if (c > count) {
        index = i;
        count = c;
        i += count - 1;
    }
}
System.out.println(Arrays.toString(arr));
System.out.printf("Starting from %d get %d%n", index, count);
System.out.println(Arrays.toString(Arrays.copyOfRange(arr, index, index + count)));

哪个输出

[2, 1, 1, 3, 3, 2, 2, 2, 2, 1, 1]
Starting from 5 get 4
[2, 2, 2, 2]

¹ Java数组不会覆盖toString()，因此您将获得数组的哈希码。

Answer 3

以下是您的解决方案：

package com.sujit;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class Test {
    public static int count = 0;
    public static void main(String[] args) {
        Integer[] arr= {2, 1, 1, 3, 3, 2, 2, 2, 2, 1 ,1}; //test array
        List<Integer> resultList =Arrays.asList(arr);
        List<Integer> maxOccurence = new ArrayList<Integer>();
        Set<Integer> set = new HashSet<>();

        for (Integer integer : resultList) {
            set.add(integer);
        }
        for (Integer integer : set) {
            int freq = Collections.frequency(resultList, integer);
            maxOccurence.add(freq);
            System.out.println("Element : "+integer+"  Occurences= "+freq);
        }
        System.out.println(Collections.max(maxOccurence));
    }
}

如何在Java中显示数组中最大相同的相邻元素

3 个答案: