Explication détaillée de l'implémentation de l'arbre binaire Java et des cas d'application spécifiques

class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;
    TreeNode(int x) { val = x; }
}

public class TreeBuilder {
    public TreeNode buildTree(int[] array) {
        if (array == null || array.length == 0) {
            return null;
        }
        return build(array, 0, array.length - 1);
    }

    private TreeNode build(int[] array, int start, int end) {
        if (start > end) {
            return null;
        }
        int mid = (start + end) / 2;
        TreeNode root = new TreeNode(array[mid]);
        root.left = build(array, start, mid - 1);
        root.right = build(array, mid + 1, end);
        return root;
    }
}

public class TreeSearch {
    public TreeNode search(TreeNode root, int target) {
        if (root == null || root.val == target) {
            return root;
        }
        if (root.val > target) {
            return search(root.left, target);
        } else {
            return search(root.right, target);
        }
    }
}

public class TreeInsert {
    public TreeNode insert(TreeNode root, int target) {
        if (root == null) {
            return new TreeNode(target);
        }
        if (root.val > target) {
            root.left = insert(root.left, target);
        } else if (root.val < target) {
            root.right = insert(root.right, target);
        }
        return root;
    }
}

public class TreeDelete {
    public TreeNode delete(TreeNode root, int target) {
        if (root == null) {
            return null;
        }
        if (root.val > target) {
            root.left = delete(root.left, target);
        } else if (root.val < target) {
            root.right = delete(root.right, target);
        } else {
            if (root.left == null && root.right == null) {
                return null;
            } else if (root.left == null) {
                return root.right;
            } else if (root.right == null) {
                return root.left;
            } else {
                TreeNode min = findMin(root.right);
                root.val = min.val;
                root.right = delete(root.right, min.val);
            }
        }
        return root;
    }

    private TreeNode findMin(TreeNode node) {
        while (node.left != null) {
            node = node.left;
        }
        return node;
    }
}

public class TreeFindKth {
    private int cnt = 0;

    public int kthSmallest(TreeNode root, int k) {
        if (root == null) {
            return Integer.MAX_VALUE;
        }
        int left = kthSmallest(root.left, k);
        if (left != Integer.MAX_VALUE) {
            return left;
        }
        cnt++;
        if (cnt == k) {
            return root.val;
        }
        return kthSmallest(root.right, k);
    }
}

public class TreeFindMinK {
    public List<Integer> kSmallest(TreeNode root, int k) {
        List<Integer> result = new ArrayList<>();
        Stack<TreeNode> stack = new Stack<>();
        TreeNode current = root;
        while (current != null || !stack.isEmpty()) {
            while (current != null) {
                stack.push(current);
                current = current.left;
            }
            current = stack.pop();
            result.add(current.val);
            if (result.size() == k) {
                return result;
            }
            current = current.right;
        }
        return result;
    }
}

public class TreeDepth {
    public int maxDepth(TreeNode root) {
        if (root == null) {
            return 0;
        }
        return Math.max(maxDepth(root.left), maxDepth(root.right)) + 1;
    }
}