java - BST 从 Java 插入到 C

Question

我目前正在学习 C 语言，并且在 Java 方面有很多经验。

我试图在 BST 上实现插入操作，我在 Java 中成功地完成了它，在 C 中的类似代码导致它失败，请有人帮我解决这个问题。

//Java代码(我用过泛型，其中Key是Comparable，另一个泛型是Value)

private class Node {
        private Value value;
        private Key key;
        private Node left, right;

    public Node(Key key, Value value) {
        this.value = value;
        this.key = key;
    }
}

public void put(Key key, Value value) {
    root = put(root, key, value);
}

public Node put(Node x, Key key, Value value) {

    if (x == null)
        return new Node(key, value);

    int cmp = key.compareTo(x.key);

    if (cmp < 0)
        x.left = put(x.left, key, value);
    else if (cmp > 0)
        x.right = put(x.right, key, value);
    else
        x.value = value;
    return x;
}

//C代码

struct Node {
    int key;
    int value;
    struct Node *left, *right;
};

struct Node *root;

struct Node *put(struct Node *x, int key, int value) {

    if (x == NULL) {
        struct Node *newNode = malloc(sizeof(struct Node));
        return newNode;
    }

    if (key < x->key)
        x->left = insert(x->left,key,value);
    else if (key > x->key)
        x->right = insert(x->right,key,value);
    else
        x->value = value;
    return x;
}

void putMain(int key, int value) {
    root = insert(root, key, value);
}

Answer 1

好像你没有初始化newNode

struct Node *newNode = malloc(sizeof(struct Node));
newNode->key = key;
newNode->value = value;
newNode->left = NULL;
newNode->right = NULL;
return newNode;