Java for LeetCode 160 Intersection of Two Linked Lists

標籤：

Write a program to find the node at which the intersection of two singly linked lists begins.

 

For example, the following two linked lists:

A:          a1 → a2                                        c1 → c2 → c3                               B:     b1 → b2 → b3

begin to intersect at node c1.

解題思路：

先遍曆兩個list的長度，然後長的減去短的，之後同時遍曆即可，JAVA實現如下：

    public ListNode getIntersectionNode(ListNode headA, ListNode headB) {        if(headA==null||headB==null)        return null;        int lengthA=0,lengthB=0;        ListNode tempA=headA,tempB=headB;    while(tempA!=null){    tempA=tempA.next;    lengthA++;        }    while(tempB!=null){    tempB=tempB.next;    lengthB++;        }    if(lengthB>lengthA){    tempA=headA;    headA=headB;    headB=tempA;    int temp=lengthA;    lengthA=lengthB;    lengthB=temp;    }    int length=lengthA-lengthB;    while(length-->0)    headA=headA.next;    while(headA!=null){    if(headA==headB)    return headA;    headA=headA.next;    headB=headB.next;    }    return headA;     }

 

Java for LeetCode 160 Intersection of Two Linked Lists