java - 识别列表中重复项的索引位置并获取 Java 中另一个列表的已识别索引处的元素

Question

我有两个列表，分别是“src”和“dest”。 src 包含一些重复项。我需要识别重复元素的索引。识别索引后，我想从“dest”列表的相同索引位置获取元素

Answer 1

这是执行此操作的算法:

1. Create a HashMap <Integer,List<Integer> >  hm = new   HashMap <Integer,List<Integer> >();
2. Iterate through the source list and fill this HashMap such that The key is the each  number that you see and value will be a list that contains the list of indexes
 int counter = 0;
 for(Integer number : src){
     If(hm.contains(number){
       List<Integer> l = hm.get(number);
       l.append(counter);
     }
     else{
       List<Integer> l = new List<Integer>();
       l.add(counter);
     }

 }
3. Using these that were stored in Hashmap  to (print / fetch) the elements of destination list.