相交链表

[pwstrick]

160. 相交链表

/**
 * Definition for singly-linked list.
 * function ListNode(val) {
 *     this.val = val;
 *     this.next = null;
 * }
 */

/**
 * @param {ListNode} headA
 * @param {ListNode} headB
 * @return {ListNode}
 */
var getIntersectionNode = function(headA, headB) {
    let A = headA,
        B = headB,
        checkA = true,
        checkB = true;
    while(A || B) {
        if(A && B && (A == B)) {
            return A;
        }
        if(A) {
            A = A.next
        }else if(checkA) {
            A = headB;
            checkA = false;
        }
        if(B) {
            B = B.next
        }else if(checkB){
            B = headA;
            checkB = false;
        }
    }
    return null;
};