C，双向链表问题

我正在尝试从用户那里读取关于客户的输入。C，双向链表问题

输入：迈克，404禁止日，北卡罗来纳州，27607,123.78

然后客户添加到按字母顺序排序，双向链表。用户可以选择插入条目，删除和条目，或查看列表。添加用户控件后...我的sscanf无法正常工作了。我无法弄清楚为什么。我不明白为什么我无法在用户控制版本中打印客户价值。

此外，任何意见/关于更新节点在前场的语法联系将是非常有益的：P

预先感谢您

工作（没有用户控制）：

#include<stdio.h> 
#include<stdlib.h> 
#include<string.h> 
#define MAXNAMELEN 19 
#define MAXADDRLEN 49 
#define MAXCITYLEN 19 
#define MAXSTATELEN 2 

struct aNode { 
    char name[MAXNAMELEN]; 
    char address[MAXADDRLEN]; 
    char city[MAXCITYLEN]; 
    char state[MAXSTATELEN]; 
    int zip; 
    float balance; 
    struct aNode *next; 
    struct aNode *prev; 
}; 

typedef struct aNode node; 
struct aNode *dLList; 

void read(); 
void input(); 
void print(); 
void delete(); 
int insertSort(node*); 

int main() { 

    //from text file 
    read(); 

    input(); 
     /* 
    int choice; 
    while(1) { 
     printf("\n1.INSERT\n2.DELETE\n3.DISPLAY\n4.END\n"); 
     printf("Enter choice:"); 
     scanf("%d",&choice); 
     switch(choice) { 
     case 1: 
      input(); 
      break; 
     case 2: 
      delete(); 
      break; 
     case 3: 
      print(); 
      break; 
     case 4: 
      exit(0); 
     } 
    } 
    */ 
    return(0); 
} 

//TODO 
void read() { 

} 

void input() { 

    struct aNode *current; 
    current = (struct aNode *)malloc(sizeof(struct aNode)); 

    int buff = 120; 
    char temp[buff]; 

    printf("Enter data: "); 
    fgets(temp, buff, stdin); 
    sscanf(temp, "%[^,]%*c %[^,]%*c %[^,]%*c %[^,]%*c %d%*c %f", 
      current->name, current->address, current->city, current->state, 
      &current->zip, &current->balance);     

    insertSort(current); 

    //only for testing 
    printf("%s, %s, %s, %s, %5d, $%9.2f\n", 
      current->name, current->address, current->city, 
      current->state, current->zip, current->balance); 
} 

void print() { 

    struct aNode *p; 

    for(p = dLList; p != NULL; p = p->next) { 
     printf("%s, %s, %s, %s, %5d, $%9.2f\n", 
       p->name, p->address, p->city, 
       p->state, p->zip, p->balance); 
    } 
} 

//TODO 
void delete() { 

} 

int insertSort(node * current) { 

    struct aNode *p; 
    struct aNode *q; 

    p = (struct aNode *)malloc(sizeof(struct aNode)); 
    p = current; 

    //need to link to previous node 
    if(dLList == NULL || strcmp(dLList->name, p->name) > 0) { 
     p->next = dLList; 
     p->prev = NULL; 
     return(0); 
    }else { 
     q = dLList; 
     while(q->next != NULL && strcmp(q->next->name, q->name) < 0) { 
      q = q->next; 
     } 
     p->next = q->next; 
     q->next = p; 
     return(0); 
    } 
}

输出：mike，404禁止st，raleigh，nc，27607，$ 123.78

不工作（用户控制）：

#include<stdio.h> 
#include<stdlib.h> 
#include<string.h> 
#define MAXNAMELEN 19 
#define MAXADDRLEN 49 
#define MAXCITYLEN 19 
#define MAXSTATELEN 2 

struct aNode { 
    char name[MAXNAMELEN]; 
    char address[MAXADDRLEN]; 
    char city[MAXCITYLEN]; 
    char state[MAXSTATELEN]; 
    int zip; 
    float balance; 
    struct aNode *next; 
    struct aNode *prev; 
}; 

typedef struct aNode node; 
struct aNode *dLList; 

void read(); 
void input(); 
void print(); 
void delete(); 
int insertSort(node*); 

int main() { 

    //from text file 
    read(); 

    //input(); 

    int choice; 
    while(1) { 
     printf("\n1.INSERT\n2.DELETE\n3.DISPLAY\n4.END\n"); 
     printf("Enter choice:"); 
     scanf("%d",&choice); 
     switch(choice) { 
     case 1: 
      input(); 
      break; 
     case 2: 
      delete(); 
      break; 
     case 3: 
      print(); 
      break; 
     case 4: 
      exit(0); 
     } 
    } 

    return(0); 
} 

//TODO 
void read() { 

} 

void input() { 

    struct aNode *current; 
    current = (struct aNode *)malloc(sizeof(struct aNode)); 

    int buff = 120; 
    char temp[buff]; 

    printf("Enter data: "); 
    fgets(temp, buff, stdin); 
    sscanf(temp, "%[^,]%*c %[^,]%*c %[^,]%*c %[^,]%*c %d%*c %f", 
      current->name, current->address, current->city, current->state, 
      &current->zip, &current->balance);     

    insertSort(current); 

    //only for testing 
    printf("%s, %s, %s, %s, %5d, $%9.2f\n", 
       current->name, current->address, current->city, 
       current->state, current->zip, current->balance); 
} 

void print() { 

    struct aNode *p; 

    for(p = dLList; p != NULL; p = p->next) { 
     printf("%s, %s, %s, %s, %5d, $%9.2f\n", 
       p->name, p->address, p->city, 
       p->state, p->zip, p->balance); 
    } 
} 

//TODO 
void delete() { 

} 

int insertSort(node * current) { 

    struct aNode *p; 
    struct aNode *q; 

    p = (struct aNode *)malloc(sizeof(struct aNode)); 
    p = current; 

    //need to link to previous node 
    if(dLList == NULL || strcmp(dLList->name, p->name) > 0) { 
     p->next = dLList; 
     p->prev = NULL; 
     return(0); 
    }else { 
     q = dLList; 
     while(q->next != NULL && strcmp(q->next->name, q->name) < 0) { 
      q = q->next; 
     } 
     p->next = q->next; 
     q->next = p; 
     return(0); 
    } 
}

输出：，，，，0，$ 0.00包装

来源

2011-04-27 beowulf3

问题是scanf不会消耗选择字符串末尾的换行符。然后通过input()中的fgets调用读取，因此输入字符串为空（除\n字符外）。

这为我工作：

fgets(temp, buff, stdin); 
sscanf(temp, "%d",&choice);

来源

2011-04-27 19:14:06 NicolasP

工作，谢谢:)你说“为你工作”？你在做同样的事情吗？：P 有关AShelly在下面写下的任何建议将会有所帮助。我不太明白他/她在暗示什么。 – beowulf3 2011-04-27 19:20:16

@ beowulf3不，我的意思是我在发布前试过:) – NicolasP 2011-04-27 19:22:16

错误：P感谢 – beowulf3 2011-04-27 19:24:35

是dLList被初始化到任何地方为空？
而且，即使它是，当你插入一个新的节点到一个空的列表中，似乎没有被设置为第一个节点。

来源

2011-04-27 18:45:35 AShelly

没有，唯一的 “= NULL” 发生在insertSort（）。 “p-> prev = NULL” – beowulf3 2011-04-27 18:49:23

所以它没有被初始化。您需要在开始时将其设置为NULL，然后在InsertSort中，每当您在列表头部插入节点（包括第一个节点）时，执行'dLList = current;'。 – AShelly 2011-04-27 18:52:31

从main（）开始？或之前？我把它放在前面：错误嘉豪。之后：不打印的问题。我把“dLList = p;”在insertSort中的if语句中。 – beowulf3 2011-04-27 18:57:48

C，双向链表问题

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