CODEWITHSUNDEEP
javatimeiteratortreeset
Kamil
Kamil

Reputation: 149

Java, TreeSet. Can we iterate elements from not first element?

Good day.

I use TreeSet, for example TreeSet<Integer> t. And I want to print all numbers from set t between x and y.

void print(Integer x,Integer y, TreeSet<Integer> t){
...
}

How to do it? Of Course I can get t.iterator(), and iterator all numbers from set and check is it greats x and less y. Time complexity is y steps. but if y-x is small. It will be better to get t.higher() and after that iterate the elements in set until it less than y. This solution can be implemented in C++. And it's time complexity is log (t.size())+(y-x).

How to do in in Java?

Upvotes: 0

Views: 235

Answers (1)

ale64bit
ale64bit

Reputation: 6242

You can use the SortedSet interface (which TreeSet implements). For example:

SortedSet<Integer> set = new TreeSet<Integer>();

for (int i = 1; i <= 5; ++i) {
    set.add(i);
}

int from = 2;
int to = 4;
for (int x : set.subSet(from, to+1)) { // Note that the higher bound is exclusive.
    System.out.println(x);
}

Output:

2
3
4

Upvotes: 1

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