Intersection Between Two Linked List

题目:
找出两个链表的交点。

解题思路：
1.可以用double for loop
2.可以用set先将一个链表的元素存起来。
3.可以直接用双指针来做。


代码:

int printUnion(int arr1[], int arr2[], int m, int n) {
    int i = 0, j = 0;
    while (i < m && j < n)
    {
        if (arr1[i] < arr2[j])
            System.out.print(arr1[i++]+" ");
        else if (arr2[j] < arr1[i])
            System.out.print(arr2[j++]+" ");
        else        {
            System.out.print(arr2[j++]+" ");
            i++;
        }
    }

  /* Print remaining elements of     the larger array */    while(i < m)
        System.out.print(arr1[i++]+" ");
    while(j < n)
        System.out.print(arr2[j++]+" ");

    return 0;
}