8.相交链表

160. 相交链表 - 力扣（LeetCode）

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/*
解题思路：
此题可以先计算出两个链表的长度，让长的链表先走相差的长度，然后两个链表同时走，直到遇到相同的节点，即为第一个公共节点
*/

struct ListNode *getIntersectionNode(struct ListNode *headA, struct ListNode *headB){int lenA = 0, lenB = 0;struct ListNode* curA = headA, *curB = headB;//计算链表长度while(curA) {++lenA;curA = curA->next;}while(curB) {++lenB;curB = curB->next;}int gap = abs(lenA-lenB);struct ListNode* longList = headA, *shortList = headB;if(lenA < lenB) {longList = headB;shortList = headA;}//让长链表先走几步while(gap--){longList = longList->next;}//两个链表同时走，直到遇到相同的节点while(longList && shortList){if(longList == shortList) {return longList;}else {longList = longList->next;shortList = shortList->next;}}return NULL;
}