java - 删除 ArrayList 中的重复项

Question

对于此作业，我将编写一个方法removeDuplicates，该方法将排序的字符串ArrayList 作为参数，并从列表中消除任何重复项。

例如，假设名为 list 的变量包含以下值:

{"be", "be", "is", "not", "or", "question", "that", "the", "to", "to"} 

调用removeDuplicates(list)后，列表应存储以下值:

{"be", "is", "not", "or", "question", "that", "the", "to"}

我几乎已经把它记下来了，但由于某种原因，如果列表包含

["duplicate", "duplicate", "duplicate", "duplicate", "duplicate"] 

它将删除除两个之外的所有内容，从而导致[重复，重复]而不是

这是我的代码:

private static void removeDuplicates(ArrayList<String> thing) {
    for (int i = 0; i < thing.size(); i++) { // base word to compare to
        String temp = thing.get(i);

        for (int j = 0; j < thing.size(); j++) { // goes through list for match
            String temp2 = thing.get(j);

            if (temp.equalsIgnoreCase(temp2) && i != j) { // to prevent removal of own letter.
                thing.remove(j);
            }
        }
    }
}

Answer 1

问题是，即使找到重复项，您也会执行“j++”。一旦你做了“thing.remove(j);”它本质上是将所有内容向下移动一个索引值，因此您不必增加 j。

示例:

{ duplicate, duplicate, duplicate, duplicate, duplicate }

i iteration 1:
i=0 [dup, dup, dup, dup, dup]
j=0 [dup, dup, dup, dup, dup]
remove=1
j=1 [dup, dup, dup, dup]
remove=2
j=2 [dup, dup, dup]

i iteration 2:
i=1 [dup, dup, dup]
remove=0
j=0 [dup, dup]
j=1 [dup, dup]

[dup, dup]

i iteration 3 stops since 3>size of list.