题解 | #反转链表# 画图更加清晰

/*
struct ListNode {
	int val;
	struct ListNode *next;
	ListNode(int x) :
			val(x), next(NULL) {
	}
};*/
class Solution {
public:
    ListNode* ReverseList(ListNode* pHead) {
        if(!pHead) {
            return pHead;
        }
        ListNode *curr = pHead;
        ListNode *prev = nullptr;
        while(curr) {
            // 保存next
            ListNode *next = curr->next;
            // 将next指向prev
            curr->next = prev;
            // 节点前移
            prev = curr;
            curr = next;
        }
        return prev;
    }
};