1 #include 
     
        2 #include 
      
         3   4 typedef struct node  5 {  6         int  num;  7         struct node* next;  8 }node;  9  10 node *head = NULL; 11  12 node *make_node(int data) 13 { 14         node *p = (node *)malloc(sizeof(node)); 15  16         if(p == NULL) 17         { 18                 return NULL; 19         } 20         else 21         { 22                 p -> num = data; 23                 p -> next = NULL; 24         } 25         return p; 26 } 27  28 void insert_node_head(node *p) 29 { 30         p -> next = head; 31         head = p; 32 } 33  34 void insert_node_tail(node *p) 35 { 36         node *p1 = head; 37         node *end = NULL; 38         if(head == NULL) 39         { 40                 head = p; 41         } 42         else 43         { 44                 while(p1 -> next  != NULL) 45                 { 46                         p1 = p1 -> next; 47                 } 48                 p1 -> next = p; 49                 p1 = p; 50                 p -> next = NULL; 51         } 52 } 53  54 void free_node(node *p) 55 { 56         free(p); 57 } 58  59 void traverse() 60 { 61         node *p = head; 62         if( p == NULL) 63         { 64                 printf("no num/n"); 65         } 66         while(p != NULL) 67         { 68                 printf("%d  ",p -> num); 69                 p = p -> next; 70         } 71         printf("\n"); 72 } 73  74 node *find(int n) 75 { 76         node *p = head; 77         while(p != NULL) 78         { 79                 if(n == p -> num) 80                 { 81                         return p; 82                 } 83                 p = p -> next; 84         } 85         return NULL; 86 } 87  88  89 void rm_node(node *p) 90 { 91         if(p == head) 92         { 93                 head = head  -> next; 94                 p -> next = NULL; 95                 return; 96         } 97         else 98         { 99                 node *pre = head;100                 while(pre != NULL)101                 {102                         if(pre -> next == p)103                         {104                                 pre -> next = p -> next ;105                                 p -> next = NULL;106                                 return ;107                         }108                         pre = pre -> next;109                 }110         }111 }112 113 void destory()114 {115         node *p = head ;116         while(head != NULL)117         {118                 head = head -> next;119                 free_node(p);120                 p = head;121         }122 }123 int main()124 {125         node *p = make_node(1);126         insert_node_tail(p);127 128         p = make_node(3);129              insert_node_tail(p);130 131         p = make_node(5);132          insert_node_tail(p);133 134         p = make_node(7);135          insert_node_tail(p);136 137         traverse();138 139         int  a = 3;140         p = find(3);141         if(p == NULL)142         {143                 printf("can not find num3\n");144         }145         else146         {147                 printf("%d\n",p -> num);148         }149         destory();150         traverse();151 }