数据结构作业

#include <stdio.h>
#include <stdlib.h>

   typedef int DataType;
   struct node{
       DataType data;
       struct node *next;
   };
   typedef struct node* PNode;
PNode creat_node();
PNode insert_node(PNode node,int num);
void delectLowerThanZero_node(PNode node);
void printf_node(PNode node);





   int main() {
PNode node=creat_node();

int n,m;
scanf("%d",&n);
for (int i = 0; i < n; ++i) {
scanf("%d",&m);
   insert_node(node,m);
}

printf("after insert:
");
printf_node(node);

delectLowerThanZero_node(node);

printf("after delect:
");
printf_node(node);
    return 0;
}

PNode creat_node(){
    PNode p;
    p=(PNode)malloc(sizeof(struct node));
    if(p!=NULL){

        p->next=NULL;
        return p;
    }
    return printf("creat fail!!!");
}

PNode insert_node(PNode node,int num){
if(node==NULL)return printf("insert fail!!!");
PNode p=(PNode)malloc(sizeof(struct node));
if(p!=NULL){
p->data=num;
    p->next=NULL;
}
PNode q=node;
while(q->next!=NULL){
    q=q->next;
}
q->next=p;

}

   void delectLowerThanZero_node(PNode node){
       if(node==NULL){
           printf("NULL");
           return;
       }
       PNode q,p;
       q=node;
       p=node->next;
       while(p!=NULL){
           if(p->data<0){
               q->next=p->next;
           free(p);
           p=q->next;
           }
           q=p;
           p=p->next;
       }
   }

   void printf_node(PNode node){
      if(node==NULL)
          return;
       PNode p=node->next;
       while(p!=NULL){
           printf("%d ",p->data);
           p=p->next;
       }
       printf("
");
   }