C语言 线性链表 节点的创建、添加和删除

注释说明以后再补，先给程序

#include 
#include 

typedef struct svit
{
    int  x ;    
    struct svit  *next ;
} s ;

s *add (s *hd, int m)
{
    s *p = NULL, *pr = hd;    
    int x;    
    p = (s *)malloc(sizeof(s)) ;    
    if (p == NULL)    
    {   
         printf("errorn") ;        
         exit (0) ;    
    }    
    if (hd == NULL)    
    {   
         hd = p ;    
    }    
    else    
    {   
         while (pr->next != NULL)        
         {     
                pr = pr->next ;        
         }        
         pr->next = p ;    
    }     
    //printf( "输入第%d个整数:", m) ;    
    scanf("%d", &x) ;    
    p->x = x ;    
    p->next = NULL ;    
    return hd ;
}

void show (s *hd)
{
    s *p = hd;    
    int j = 1;    
    while (p != NULL)    
    {
          printf("节点:%d  数据:%dn", j , p->x) ;        
          p = p->next ;        
          j++ ;    
    }
}

void up (s *hd)
{
    s *p = hd , *pr = NULL;    
    while (p != NULL)    
    { 
          pr = p ;        
          p = p->next ;        
          free (pr) ;    
    }
}

s * sc (s *hd, int a)
{
    s *p = hd, *pr = hd;    
    if (hd == NULL)    
    {  
          printf("为空表n") ;        
          return (hd) ;    
    }    
    while (p->x != a && p->next != NULL)    
    {  
          pr = p ; 
          p = p->next;    
    }    
    if (p->x == a)    
    {  
          if (p == hd)        
          {    
                 hd = p->next ;        
          }        
          else        
          {      
                 pr->next = p->next ;        
          }        
          free(p) ;    
    }    
    else    
    {  
          printf("未找到n") ;    
    }    
    return hd ;
}

s * tj (s *hd, int a)
{
    s *p = hd, *pr = hd, *t = NULL;    
    t = (s *)malloc(sizeof(s)) ;    
    if (t == NULL)    
    {   
         printf("errorn") ;        
         exit (0) ;    
    }    
    t->x = a ;    
    t->next = NULL ;    
    if (hd == NULL)    
    {   
         hd = t ;     
    }    
    else    
    {    
         while (a > p->x && p->next != NULL)        
         {      
               pr = p ;            
               p = p->next ;        
         }        
         if (a <= p->x)        
         {       
               if (p == hd)            
               {         
                      t->next = p ;                
                      hd = t ;            
               }            
               else            
               {           
                      t->next = p ;                
                      pr->next = t ;            
               }        
         }        
         else        
         {       
               p->next = t ;        
         }    
    }    
    return hd ;
}

int jy (int x, int n)
{
    while (x != 1)    
    {  
          while (getchar() != 'n') ;        
          printf("输入无效，请重新输入:n") ;        
          x = scanf("%d", &n) ;    
    }    
    return n ;
}

void mu(s *hd)
{
    int b, x, s;    
    printf("选择你想进行的操作,并输入你想进行的操作前的序号:n1:删除节点n2:添加节点n3:退出程序") ;    
    s = scanf("%d", &b) ;    
    b = jy(s, b) ;    
    if (b == 1)    
    {   
         printf("请输入你要删除的节点数据:n") ;        
         s = scanf("%d", &x) ;        
         x = jy(s, x) ;        
         show(sc(hd, x)) ;    
     }    
     else if (b == 2)    
     {  
          printf("请输入你要添加的节点数据:") ;        
          s = scanf("%d", &x) ;        
          x = jy(s, x) ;        
          show(tj(hd,x)) ;    
     }    
     else if (b == 3)    
     {   
          exit (0) ;    
     }    
     else    
     {   
          printf("输入无效n") ;        
          mu(hd) ;    
     }
} 

int main(void)
{
    s *hd = NULL;    
    int n, i = 0, x = 0;    
    char j;    
    printf("输入想输入数的个数n:") ;    
    x = scanf("%d", &n) ;    
    n = jy(x, n) ;    
    printf("输入%d个整数:", n) ;    
    for ( ; i