Question

我正在尝试用C编程中的ID值和字符串名称来编写B +树的结构。但我有一个问题。在程序中，当我写15个ID和名称时，所有ID值排序和显示但名称都没有显示ID，我不知道为什么，但它应该有显示。也许我在第21行遗漏了一些东西，它可能是temp->name = word但是Visual程序不接受它。

这是我的代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct bin_tree
{
    int data;
    char name[30];
    struct bin_tree * right, * left;
};
typedef struct bin_tree node;

void insert(node **tree, int val, char  word[30])
{
    node *temp = NULL;
    if(!(*tree))
    {
        temp = (node *)malloc(sizeof(node)); //Dynamic Allocation
        temp->left = NULL;
        temp->right = NULL;
        temp->data = val;
        temp->name[30]= word; //temp->name = word; - HATA
        *tree = temp;
        return;
    }
    if(val < (*tree)->data)
    {
        insert(&(*tree)->left, val,word);
    }
    else if(val > (*tree)->data)
    {
        insert(&(*tree)->right, val,word);
    }
}

struct tree *delet(struct bin_tree *ptr, int x)
{
    struct bin_tree *p1,*p2;
    if(!ptr)
    {
        printf("ID not found");
        return(0);
    }
    else
    {
        if(ptr->data < x)
        {
            delet(ptr->right,x); //ptr->right=delet(ptr->right,x);

        }
        else if (ptr->data >x)
        {
            delet(ptr->left,x); //ptr->left=delet(ptr->left,x);
        }
        else
        {
            if(ptr->data == x)
            {
                if(ptr->left == ptr->right)
                {
                    free(ptr);
                    return(NULL);
                }
                else if(ptr->left==NULL)
                {
                    p1=ptr->right;
                    free(ptr);
                }
                else if(ptr->right==NULL)
                {
                    p1=ptr->left;
                    free(ptr);
                }
                else
                {
                    p1=ptr->right;
                    p2=ptr->right;
                    while(p1->left != NULL)
                        p1=p1->left;
                    p1->left=ptr->left;
                    free(ptr);
                }
            }
        }
    }
}

node* search(node ** tree, int val)
{
    if(!(*tree))
    {
        return NULL;
    }

    if(val < (*tree)->data)
    {
        search(&((*tree)->left), val);
    }
    else if(val > (*tree)->data)
    {
        search(&((*tree)->right), val);
    }
    else if(val == (*tree)->data)
    {
        return *tree;
    }
}

void print_preorder(node * tree)
{

    if (tree)
    {
        printf("%d - %s ->",tree->data, tree->name); // Preorder ID - Name çıkmıyor
        print_preorder(tree->left);
        print_preorder(tree->right);
    }

}

void print_inorder(node * tree)
{   
    if(tree)
    {
        print_inorder(tree->left);
        printf("%d - %s ->",tree->data,tree->name); //Inorder ID - Name çıkmıyor
        print_inorder(tree->right);
    }
}

void print_postorder(node * tree)
{
    if (tree)
    {
        print_postorder(tree->left);
        print_postorder(tree->right);
        printf("%d - %s ->",tree->data,tree->name); //Postorder ID - Name çıkmıyor
    }       
}

int main()
{
    node *root;
    node *tmp;
    int a; //ID for Add func.
    int item_no; //Id for delete func.
    int z; //ID for search func.
    int i=0;

    char ans,b[100],c;

    root=NULL;
    while(ans!='5')
    {
        printf("1. Add\n");
        printf("2. Delete\n");
        printf("3. Search\n");
        printf("4. Display\n");
        printf("5. Exit\n");
        printf("Enter the choice: ");
        scanf("%s",&ans);
        switch(ans)
        {
        case '1':

            {
                printf("Enter the Student ID: ");
                scanf("%d",&a);
                printf("Enter the student's name: ");
                scanf("%d", &c);
                while((c != '\n' && i<30)
                {
                    b[i++] = c;
                }
                b[i] = '\0';
                insert(&root,a,b);
                i=0;
                break;
            }
        case '2':
            {
                printf("Enter the ID: ");
                scanf(" %d",&item_no);
                delet(root, item_no);
                break;
            }
        case '3':
            {
                printf("Enter the Student ID: ");
                scanf("%d",&z);
                tmp = search(&root, z);
                if (tmp)
                {
                    printf("Student ID: %d\nStudent name: %s\n", tmp->data, tmp->name);
                }
                else
                {
                    printf("Data not found.\n");
                }
            }
        case '4':
            {
                printf("\nPre Order Display: ");
                print_preorder(root);

                printf("\nIn Order Display: ");
                print_inorder(root);

                printf("\nPost Order Display: ");
                print_postorder(root);
            }
        case '5':
            {   
                printf("\nDone.");
                exit (0);
            }
        default :
            {
                printf("Wrong choice!\n");
                break;
            }
        }
    }
    return 0;
}

Answer 1

你想要的是复制字符：

strcpy(temp->name, word);

（您尝试将char数组分配给单个char，这也恰好超出了数组的大小。name的大小为30，因此有效索引的范围为0到29 。）

B +树的结构与字符串名称

1 个答案: