[LeetCode]Remove Duplicates from Sorted List

最新推荐文章于 2022-04-03 22:46:44 发布

原创最新推荐文章于 2022-04-03 22:46:44 发布 · 1.1k 阅读

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本文提供了一种使用C++实现的高效方法来移除单链表中的连续重复元素。通过迭代方式，仅保留不重复的节点，从而简化链表结构。此算法避免了额外的空间开销，易于理解和实现。

struct ListNode {
	int val;
	ListNode *next;
	ListNode(int x) : val(x), next(NULL) {}
};


class Solution {
//just record the previous pointer, and the current pointer
public:
	ListNode *deleteDuplicates(ListNode *head) {
		// Start typing your C/C++ solution below
		// DO NOT write int main() function
		ListNode* prev = NULL;
		ListNode* cur = head;
		while (cur)
		{
			if(!prev) prev = cur;
			else if(cur->val != prev->val)
			{
				prev->next = cur;
				prev = cur;
			}
			cur = cur->next;
		}
		if(prev) prev->next = NULL;
		return head;
	}
};

second time

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode *deleteDuplicates(ListNode *head) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        if(head == NULL) return head;
        ListNode* prev = head;
        ListNode* cur = head->next;
        while(cur != NULL)
        {
            if(prev->val != cur->val)
            {
                prev->next = cur;//... need release memory?
                prev = prev->next;
            }
            cur = cur->next;
        }
        prev->next = NULL;
        return head;
    }
};