C linklist -練習

 [心得] : 1.注意反轉.與delete






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

char input_name[255];
int input_age;

struct Node{
  char name[255];
  int age;
  struct Node *next;      
      
};


struct Node *first=NULL;
struct Node *temp=NULL;
struct Node *current=NULL; 

void EnterData()
{
  printf("please input name :");
  scanf("%s",&input_name);
  printf("please input age :");
  scanf("%d",&input_age);
          
}

void CreateFirstNode(int input_age,char* input_name)
{

    first = (struct Node *)malloc(sizeof(struct Node)); 
    strcpy(first->name,input_name);
    first->age =input_age;
    current =first;
    current->next =NULL;                               
                                     
}

void InsertNode(int input_age,char *input_name)
{
  temp=(struct Node*)malloc(sizeof(struct Node));
  temp->age =input_age;
  strcpy(temp->name,input_name);  
  temp->next =NULL; 
  current->next =temp;
  current =temp;  
}

void deleteNode(char* input_name)
{

  struct Node *temp_prev=NULL;  
  temp =first;
  if(temp ==NULL)
   printf("NO data to delete");
  while(temp!=NULL)
  {
    if(strcmp(first->name,input_name)==0)
    {
      first = temp->next;
      free(temp);
    }     
    if(strcmp(temp->name,input_name)==0)  
    {
      temp_prev->next =temp->next;   //要先把欲刪除的Node_B(temp)的前一個Node_A(temp_prev-)指到B的後面一個Node_C(temp->next)
      free(temp);                                 
    }
    temp_prev=temp;//這兩行指再繼續下一個點
    temp=temp->next;
  }     
    
}  
   
void display()
{
   temp =first;  
   if(first==NULL)
      printf("NO data");
   else
   {
      while(temp!=NULL)
      {
       printf("name = %s, age = %d \n",temp->name,temp->age);
       temp =temp->next;            
      }  
       
   }  
}
void Invert_linklist()
{
  struct Node *p=NULL;
  p=first; 
  temp=NULL;
  while(first->next != NULL)
  {
     first = p->next;  //先把first assign到下一個點
     p->next = temp; //p再指回去前面的點
     temp=p;  //再繼續反轉下一個點
     p=first;
  }
   p->next =temp;  //這行很重要,要記得最後要再把p下一個點,指到temp
}


void selsectFun()
{
        int i;
        printf("------------------------------------\n");
        printf("|1 Add Node\n");
        printf("|2 Delete Node\n");
        printf("|3 Display List Node\n");
        printf("|4 Display and Invert List Node\n");
        printf("|-1 Exit\n");
        printf("------------------------------------\n");
        do
        {
                printf("Enter the function number>");
                scanf("%d",&i);
                if(i == 1)
                {
                        if(first == NULL)
                        {
                                EnterData();
                                CreateFirstNode(input_age,input_name);
                        }
                        else
                        {
                                EnterData();
                                InsertNode(input_age,input_name);
                        }
                }
                else if(i == 2)
                {
                        printf("Enter the person's name>");
                        scanf("%s",&input_name);
                        deleteNode(input_name);
                }
                else if(i == 3)
                        display();
                else if(i == 4) {
                        Invert_linklist();
                        display();
                        }   
                else if(i == -1)
                {}
                else
                        printf("Wrong function number!!\n");
        }while(i != -1);
}
int main()
{
        selsectFun();
        system("pause");
        return 0;
}