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

struct node
{
    char* data;
    struct node* left;
    struct node* right;
};
typedef struct node Node;
int count;

void initnode(Node* root)
{
    root->right = NULL;
    root->left = NULL;

}
void addtree(Node* root, char* input)
{
    char res = strcmp(input, root->data);
    printf("\nres %d\n", res);
    if(res < 0)
    {
        if(root->left == NULL)
        {
            Node *leaf = (Node *)malloc(sizeof(Node));
            initnode(leaf);
            root->left = leaf;
            //(root)->left->data = malloc(strlen(input)   1);
            strcpy(leaf->data, input);
        }else
        {
            addtree(root->left, input);
        }
        return;
    }
    if(res > 0)
    {
        if(root->right == NULL)
        {
            Node *leaf = (Node *)malloc(sizeof(Node));
            initnode(leaf);
            root->right = leaf;
            //(root)->right->data = malloc(strlen(input)   1);
            strcpy(leaf->data, input);
        }else
        {
            addtree(root->right, input);
        }
        return;
    }


}
void printtree(Node *root)
{
    if( root->left == NULL ) {
        printf("%s\n", root->data);
        if(root->right != NULL)
        {
            printtree( root->right);
        }

    }else
    {
        printtree(root->left);
    }
}
int main(void) {

    Node *root = NULL;
    char input[128], initial[128];
    int choice;
    root = (Node *)malloc(sizeof(Node));
    initnode(root);
    printf("Please enter the first and root word");
    scanf("%s", initial);
    strtok(initial, "\n" );
    strcpy(root->data, initial);



    while(choice != 0)
    {
        printf("Press 0 to exit\n");
        printf("Press 1 to enter new word\n");
        printf("Press 2 to print tree\n");
        scanf("%d", &choice);
        getchar();
        if(choice == 1)
        {
            printf("Please enter a string: ");
            fgets(input, sizeof input, stdin);
            strtok(input, "\n" );
            printf("You entered %s", input);
            addtree(root, input);
        }else if(choice == 2)
        {
            printtree(root);
        }
    }
    return 0;
}

Output:

Please enter the first and root wordHello
Press 0 to exit
Press 1 to enter new word
Press 2 to print tree
1
Please enter a string:Hi
 You entered Hi
res 1
Press 0 to exit
Press 1 to enter new word
Press 2 to print tree
2
Hi
Hi
Press 0 to exit
Press 1 to enter new word
Press 2 to print tree

Having issues making a Binary Tree that sorts words in C. I feel like my implementation is good, but cannot figure out where or why my words are overwriting each other. It should print Hello Hi and other words, but it just prints the most recently entered word. Any suggestions would be appreciated. I do not think it is my addtree function as the words are added, but maybe its that way I am passing 'root'?

CodePudding user response：

Well the first major problem of this code was, it gives a segmentation fault everytime it tries to copy the strings to the leaf or root of this binary tree. So I added a malloc statement to the addtree function for both of the if statements like;

        leaf->data = (char *)malloc(sizeof(char));
        //(root)->right->data = malloc(strlen(input)   1);
        strcpy(leaf->data, input);
...

and added to the main function like;

    root->data = (char *)malloc(sizeof(char));
    strcpy(root->data, new_initial);

And the second major problem was, my compiler gave a segmentation fault again for the while loop in the main function, because the condition was choice != 0 before there was a choice input from the user, so I added the following statement before the while loop;

    scanf("%d", &choice);

to let the code start the loop with a value other than zero. Or you can modify it just as you like. Here's the output:

Please enter the first and root wordhello
1
Press 0 to exit
Press 1 to enter new word
Press 2 to print tree
1
Please enter a string: hi
You entered hi
res 1
Press 0 to exit
Press 1 to enter new word
Press 2 to print tree
2
hello
hi
Press 0 to exit
Press 1 to enter new word
Press 2 to print tree