sm10-3main.c

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

typedef struct Node
{
    double       key;
    struct Node *left;
    struct Node *right;
    char        *str;
} Node;

int tree_find(struct Node *root, double key, char **pstr);

Node *init_node(double key)
{
    Node *node = calloc(1, sizeof(*node));
    node->key = key;
    node->left = NULL;
    node->right = NULL;
    node->str = calloc(100, sizeof(*(node->str)));
    return node;
}

int main(void)
{
    Node *node = init_node(10.000000001);
    node->left = init_node(-89.99999999);
    node->right = init_node(110.0);
    strcpy(node->str, "node");
    strcpy(node->left->str, "left node");
    strcpy(node->right->str, "right node");
    char *ans = NULL;

    printf("%d\t", tree_find(node, 10.0, &ans));
    printf("%s\n", !ans ? "(null)" : ans);
    printf("1\tnode\n\n");
    ans = NULL;

    printf("%d\t", tree_find(node, -90.0, &ans));
    printf("%s\n", !ans ? "(null)" : ans);
    printf("1\tleft node\n\n");
    ans = NULL;

    printf("%d\t", tree_find(node, 110.0, &ans));
    printf("%s\n", !ans ? "(null)" : ans);
    printf("1\tright node\n\n");
    ans = NULL;

    printf("%d\t", tree_find(node, -190.0, &ans));
    printf("%s\n", !ans ? "(null)" : ans);
    printf("0\t(null)\n\n");
    ans = NULL;

    printf("%d\t", tree_find(node, 210.0, &ans));
    printf("%s\n", !ans ? "(null)" : ans);
    printf("0\t(null)\n\n");
    ans = NULL;

    printf("%d\t", tree_find(node, -50.0, &ans));
    printf("%s\n", !ans ? "(null)" : ans);
    printf("0\t(null)\n\n");
    ans = NULL;

    printf("%d\t", tree_find(node, 50.0, &ans));
    printf("%s\n", !ans ? "(null)" : ans);
    printf("0\t(null)\n\n");
    ans = NULL;

    free(node->left->str);
    free(node->right->str);
    free(node->str);

    free(node->left);
    free(node->right);
    free(node);
}