如何從兩個數組列表中刪除公共值

Question

如何從兩個ArrayList中刪除公共值。 讓我們考慮我有兩個數組列表如下圖所示

ArrayList1= [1,2,3,4] 
ArrayList1= [2,3,4,6,7] 

我想有結果作爲

ArrayListFinal= [1,6,7] 

任何人都可以請幫我嗎？

Answer 1

這裏是你可以按照完成任務的算法：

• 構建兩個數組的聯合
• 構建兩個數組的交集
• 從工會減去路口讓你的結果

Java集合支持addAll，removeAll和retainAll。使用addAll建設工會，retainAll構建交叉口，和removeAll作減法，like this：

// Make the two lists 
List<Integer> list1 = Arrays.asList(1, 2, 3, 4); 
List<Integer> list2 = Arrays.asList(2, 3, 4, 6, 7); 
// Prepare a union 
List<Integer> union = new ArrayList<Integer>(list1); 
union.addAll(list2); 
// Prepare an intersection 
List<Integer> intersection = new ArrayList<Integer>(list1); 
intersection.retainAll(list2); 
// Subtract the intersection from the union 
union.removeAll(intersection); 
// Print the result 
for (Integer n : union) { 
    System.out.println(n); 
} 

Answer 2

SetList<Integer> A = new SetList<Integer>(); 
A.addAll({1,2,3,4}); 

SetList<Integer> B = new SetList<Integer>(); 
B.addAll({2,3,4,6,7}); 

Integer a = null; 

for (int i=0; i<A.size(); i++) 
{ 
    a = A.get(i); 

    if (B.contains(a) 
    { 
     B.remove(a); 
     A.remove(a); 
     i--; 
    } 
} 

SetList<Integer> final = new SetList<Integer>(); 
final.addAll(A); 
final.addAll(B); 

// final = { 1, 6, 7 } 

Answer 3

你實際上問了Symmetric Difference。

List<Integer> aList = new ArrayList<>(Arrays.asList(1, 2, 3, 4)); 
List<Integer> bList = new ArrayList<>(Arrays.asList(2, 3, 4, 6, 7)); 
// Union is all from both lists. 
List<Integer> union = new ArrayList(aList); 
union.addAll(bList); 
// Intersection is only those in both. 
List<Integer> intersection = new ArrayList(aList); 
intersection.retainAll(bList); 
// Symmetric difference is all except those in both.  
List<Integer> symmetricDifference = new ArrayList(union); 
symmetricDifference.removeAll(intersection); 

System.out.println("aList: " + aList); 
System.out.println("bList: " + bList); 
System.out.println("union: " + union); 
System.out.println("intersection: " + intersection); 
System.out.println("**symmetricDifference: " + symmetricDifference+"**"); 

打印：

aList: [1, 2, 3, 4] 
bList: [2, 3, 4, 6, 7] 
union: [1, 2, 3, 4, 2, 3, 4, 6, 7] 
intersection: [2, 3, 4] 
**symmetricDifference: [1, 6, 7]** 

Answer 4

您可以使用這樣的事情：

ArrayList <Integer> first = new ArrayList <Integer>(); 
    ArrayList <Integer> second = new ArrayList <Integer>(); 
    ArrayList <Integer> finalResult = new ArrayList <Integer>(); 

    first.add(1); 
    first.add(2); 
    first.add(3); 
    first.add(4); 

    second.add(2); 
    second.add(3); 
    second.add(4); 
    second.add(6); 
    second.add(7); 

    for (int i = 0; i < first.size(); i++){ 

     if (!second.contains(first.get(i))){ 

      finalResult.add(first.get(i)); 
     } 
    } 


    for (int j = 0; j < second.size(); j++){ 

     if (!first.contains(second.get(j))){ 

      finalResult.add(second.get(j)); 
     } 

    } 

我只是填充2周的ArrayList如您在您的文章中描述他們，我對他們兩個檢查針對不同的元素;如果找到了這樣的元素，我將它們添加到finalResult ArrayList中。

我希望它會幫助你:)