题解 | #JZ76 删除链表中重复的结点#

/*
struct ListNode {
    int val;
    struct ListNode *next;
    ListNode(int x) :
        val(x), next(NULL) {
    }
};
*/
class Solution {
public:
    ListNode* deleteDuplication(ListNode* pHead) {
        if(pHead == NULL){
            return NULL;
        }
        if(pHead->next == NULL){
            return pHead;
        }
        unordered_map <int,ListNode*> count_table;
        ListNode* front = pHead;
        ListNode* temp;
       
     
        while(front !=NULL){
            auto it = count_table.find(front->val);
            if ( it == count_table.end()){
                count_table.emplace(front->val,front);
              
            }
            else{
                it->second = NULL;
            }
            front = front->next;
         

        }
        front=pHead;
        pHead = NULL;
        while(front !=NULL){
            auto it = count_table.find(front->val);
            front = front->next;
          
            if( it->second == NULL){
                continue;
            }
            else{
                if(pHead == NULL){
                    pHead = it->second;
                    pHead->next = NULL;
                    temp = pHead;
                    cout<<temp->val<<endl;
                    continue;
                }
                temp->next = it->second;
                temp = temp->next;
                cout<< temp->val<<endl;
                temp->next =NULL;
            }
        }       
        return pHead;

    }
};