如何在哈希映射键中找到下一个最小值？

Question

I have a scenario where I have a map:

BiMap <Integer, String> map; 

and a list which tracks the index which are processed.

List<Integer> filled;

While processing if the filled list contains the key then I should find the next min key from the map which is already not in the filled list.

Can some one tell me is there an easy way to do this without doing many iterations?

for (int i =0 ;i <size; i++) {
    if(map.contiansKey(i)) {
        Integer min = list.contains(i) ? getNextMinFrom(map, filled) : null;
        if min != null ?System.out.println(map.get(min)) : continue;
    }
}

For Eg:

Filled - 0, 4, 5, 6

Map - (1,dfs) (4,efs) (5,sdfs) 

in the 0 th iteration..  output - dfs (1 is min)
      in 4th iteration ... output shoudl be 4efs (4 is the next min) 
.... 

The issue is I can not remove entries from the list.

Answer 1

使用以map的“ KeySet”初始化的TreeSet ，并在添加“ Any key” filled将其从“ TreeSet”中删除，因此， TreeSet的第一个元素就是您想要的

Answer 2

Is this what you want to achieve? Start from the front of the filled array and go until you find the first value that is in filled but not in the map?

public int get smallestUnusedValue() {
    for(int i = 0; i < filled.size(); i++)
        if(!map.containsKey(filled.get(i)))
            return i;
}

Answer 3

Do you need to use a HashMap specifically? Implementations of NavigableMap , such as TreeMap , provide methods to look up keys "adjacent to" a given value, without requiring an exact map. The higherEntry method seems to do what you want.