【leetcode】【单链表】【82】Remove Duplicates from Sorted List II

#include<iostream>
#include<stack>
using namespace std;

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

class Solution {
public:
	ListNode* deleteDuplicates(ListNode* head) {
		if (head == NULL || head->next == NULL)
			return head;

		ListNode* cur = head;
		ListNode* beginDelete = NULL;//要删除的起始节点
		ListNode* last = NULL;//不被删除的最后一个节点
		ListNode* temp = NULL;
		while (cur){
			beginDelete = cur;
			while (cur->next){
				if (beginDelete->val == cur->next->val)
					cur = cur->next;
				else
					break;
			}
			if (beginDelete == cur){
				head = cur;
				break;
			}else{
				cur = cur->next;
				while (beginDelete != cur){
					temp = beginDelete;
					beginDelete = beginDelete->next;
					delete temp;
				}
				beginDelete = NULL;
				head = cur;
			}	
		}//找出第一个没有重复的 如1 1 2 2 3 4 5 5 找出3；1 3 3 4 找出1
		while (cur){
			beginDelete = cur;
			while (cur->next){
				if (beginDelete->val == cur->next->val)
					cur = cur->next;
				else
					break;
			}
			if (beginDelete == cur){
				last = cur;
				cur = cur->next;
			}else{
				cur = cur->next;
				while (beginDelete != cur){//删除一个，头结点串接下一个节点
					temp = beginDelete;
					beginDelete = beginDelete->next;
					last->next = beginDelete;
					delete temp;
				}
				beginDelete = NULL;
			}
		}
		return head;
	}
	ListNode* createList(ListNode* head){
		int numOfNode;
		int value;
		cout << "please input number of listNode:";
		cin >> numOfNode;
		cin >> value;
		head = new ListNode(value);
		ListNode* cur = head;
		for (int i = 1; i < numOfNode; ++i){
			cin >> value;
			ListNode* temp = new ListNode(value);
			cur->next = temp;
			cur = temp;
		}
		return head;
	}
	void printNode(ListNode* head){
		ListNode* cur = head;
		while (cur){
			cout << cur->val << " ";
			cur = cur->next;
		}
		cout << endl;
	}
};

int main(){
	ListNode* head = NULL;
	Solution solution;
	head = solution.createList(head);
	solution.printNode(head);

	head = solution.deleteDuplicates(head);
	solution.printNode(head);

	system("pause");
	return 0;
}