leetcode/Problem281/ZigzagIterator.java at master · gorthitk/leetcode · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55


import java.util.List;

public class ZigzagIterator
{
    private final List<Integer> list1;
    private final List<Integer> list2;
    int list1Index = 0;
    int list2Index = 0;
    int currentList = -1;

    public ZigzagIterator(List<Integer> v1, List<Integer> v2)
    {
        this.list1 = v1;
        this.list2 = v2;
        currentList = !v1.isEmpty() ? 1 : !v2.isEmpty() ? 2 : -1;
    }

    public int next()
    {
        if (currentList == 1)
        {
            int value = list1.get(list1Index++);
            if (list2Index == list2.size())
            {
                currentList = list1Index == list1.size() ? -1 : 1;
            }
            else
            {
                currentList = 2;
            }
            return value;
        }
        if (currentList == 2)
        {
            int value = list2.get(list2Index++);
            if (list1Index == list1.size())
            {
                currentList = list2Index == list2.size() ? -1 : 2;
            }
            else
            {
                currentList = 1;
            }
            return value;
        }
        return -1;
    }

    public boolean hasNext()
    {
        return currentList != -1;
    }
}