面试题 02.01. 移除重复节点

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     struct ListNode *next;
 * };
 */


struct ListNode* removeDuplicateNodes(struct ListNode* head){
    int sum[30000];
    for(int i=0;i<30000;i++) //不加这个的话,初始化可能不全是0
    {
        sum[i]=0;
    }
    struct ListNode* p =(struct ListNode *)malloc(sizeof(struct ListNode)),*tail;
    p->next = NULL;
    tail = p;

    while(head)
    {
        sum[head->val]++;
        if(sum[head->val]==1)
        {
             struct ListNode* s =(struct ListNode *)malloc(sizeof(struct ListNode));
             s->val = head->val;
             s->next = NULL;
             tail->next = s;
             tail = s;
        }

        head = head->next;
    }

    return p->next;
}