将名称和数字插入到链表的末尾

Question

我的文本文件是这样的：

George Washington, 2345678 
John Adams, 3456789 
Thomas Jefferson, 4567890 
James Madison, 0987654 
James Monroe, 9876543 
John Quincy Adams, 8765432 
Andrew Jackson, 7654321 
Martin Van Buren, 6543210

有人可以提供有关我如何使用插入函数将名称和 ID 号添加到链接列表末尾的见解吗？当我运行代码时，选择选项 1 它会跳过添加名称，只要求输入整数。之后什么都没有发生。

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

//Creates node for holding student's information
struct node
{
    char name [50];
    int id;
    struct node *next;
}*head;

//Create Function Prototypes
void readDataFile ();
void insert(char *inName, char *inID);
void display(struct node *d);
int deleteID(int num);
void deleteName(char dname);


//Main function
int main()
{
    //Declare variables
    int i, num, id;
    char *name;
    char nameDelete [50];
    char nameInsert [50];
    struct node *n;

    //initialize link list
    head = NULL;

    //Read in file
    readDataFile();

    //Create list of operations utilized in program
    while (1)
    {
        printf("\nList Operations\n");
        printf("===============\n");
        printf("1.Insert\n");
        printf("2.Display\n");
        printf("3.Delete by ID\n");
        printf("4.Delete by Name\n");
        printf("5.Exit\n");
        printf("Enter your choice : ");

        if(scanf("%d", &i) <= 0)
        {
            printf("Enter only an Integer\n");
            exit(0);
        }
        else
        {
            switch(i)
            {
                case 1:
                    printf("Enter the name to insert:\n");
                    scanf("%[^\n]s", nameInsert);
                    getchar();
                    printf("Enter the ID associated with the name: ");
                    scanf("%d", &id);
                    insert(nameInsert, id);
                    break;
                case 2:
                    if (head == NULL)
                        printf("List is Empty\n");
                    else
                    {
                        printf("Elements in the list are:\n");
                    }
                    display(n);
                    break;
                case 3:
                    if(head == NULL)
                        printf("List is Empty\n");
                    else
                    {
                        printf("Enter the ID number to delete: ");
                        scanf("%d", &id);
                    }

                    if(deleteID(id))
                        printf("%d deleted successfully \n", id);
                    else
                        printf("%d not found in the list\n", id);
                    break;
                case 4:
                    if(head == NULL)
                        printf("List is Empty\n");
                    else
                    {
                        printf("Enter name to delete: ");
                        gets(nameDelete);
                    }
                case 5:
                    return 0;
                default:
                    printf("Invalid option\n");
            }
        }
    }
    return 0;
}

//Define the functions
//Function to read in the data file
void readDataFile()
{
    //Initialize the link the list
    struct node *temp;
    temp = malloc(sizeof(struct node));
    temp->next = NULL;
    head = temp;

    //Open up the file
    FILE *fp;
    fp = fopen("AssignmentOneInput.txt", "r");

    //Use memset function to copy the characters in string
    char string[100];
    memset(string, 0, 100);

    //Create while loop scan in the contents of the file
    while(fgets(string, 100, fp) != NULL)
        {
        sscanf(string, "%20[^,], %d", temp->name, &temp->id);
        temp->next = malloc(sizeof(struct node));
        temp = temp->next;
        temp->next = NULL;

        }
        fclose(fp);
}

//Function to insert a name and ID number
void insert(char *inName, char *inID)
{
    //Create temporary and helper nodes
    struct node *temp, *helper;

    //Allocate the memory for the temporary node
    temp = (struct node *)malloc(sizeof(struct node));

    //Convert character into integer value
    int intID = atoi(inID);

    //Set the data in the node
    strcpy(temp->name, inName);
    temp->id = intID;
    temp->next = NULL;

    //Create new node and add to it
    helper = (struct node *)head;

    while(helper->next != NULL)
    {
        helper = helper->next;
    }

    helper->next = temp;
    helper = temp;
    helper->next = NULL;
}

Answer 1

在选择选项中输入 1 后，标准输入将同时包含 1 和换行符，您会在下一个 scanf 语句中立即看到这些字符。

将scanf("%[^\n]s", nameInsert); 更改为scanf("%s", nameInsert); 或在获得选择选项后立即使用getchar()。