📜  计算二叉树中节点高度和深度的程序

📅  最后修改于: 2021-09-03 03:14:31             🧑  作者: Mango

给定一个由N 个节点和一个整数K组成的二叉树,任务是在二叉树中找到值为K的节点的深度和高度。

例子:

方法:该问题可以基于以下观察来解决:

按照以下步骤查找给定节点的深度:

  • 如果树为空,则打印 -1。
  • 否则,请执行以下步骤:
    • 初始化一个变量,比如dist-1
    • 检查节点K是否等于给定节点。
    • 否则,通过分别递归检查左子树和右子树来检查它是否存在于任一子树中。
    • 如果发现为真,则打印dist + 1的值。
    • 否则,打印dist

按照以下步骤查找给定节点的高度:

  • 如果树为空,则打印 -1。
  • 否则,请执行以下步骤:
    • 递归计算左子树的高度。
    • 递归计算右子树的高度。
    • 通过将上一步中获得的两个高度中的最大值加 1 来更新当前节点的高度。将高度存储在一个变量中,比如ans
    • 如果当前节点等于给定节点K,则打印ans的值作为所需答案。

下面是上述方法的实现:

C++
// C++ program for the above approach
#include 
using namespace std;
 
// Structure of a Binary Tree Node
struct Node {
    int data;
    Node *left, *right;
};
 
// Utility function to create
// a new Binary Tree Node
Node* newNode(int item)
{
    Node* temp = new Node;
    temp->data = item;
    temp->left = temp->right = NULL;
    return temp;
}
 
// Function to find the depth of
// a given node in a Binary Tree
int findDepth(Node* root, int x)
{
    // Base case
    if (root == NULL)
        return -1;
 
    // Initialize distance as -1
    int dist = -1;
 
    // Check if x is current node=
    if ((root->data == x)
 
        // Otherwise, check if x is
        // present in the left subtree
        || (dist = findDepth(root->left, x)) >= 0
 
        // Otherwise, check if x is
        // present in the right subtree
        || (dist = findDepth(root->right, x)) >= 0)
 
        // Return depth of the node
        return dist + 1;
 
    return dist;
}
 
// Helper function to find the height
// of a given node in the binary tree
int findHeightUtil(Node* root, int x,
                   int& height)
{
    // Base Case
    if (root == NULL) {
        return -1;
    }
 
    // Store the maximum height of
    // the left and right subtree
    int leftHeight = findHeightUtil(
        root->left, x, height);
 
    int rightHeight
        = findHeightUtil(
            root->right, x, height);
 
    // Update height of the current node
    int ans = max(leftHeight, rightHeight) + 1;
 
    // If current node is the required node
    if (root->data == x)
        height = ans;
 
    return ans;
}
 
// Function to find the height of
// a given node in a Binary Tree
int findHeight(Node* root, int x)
{
    // Store the height of
    // the given node
    int h = -1;
 
    // Stores height of the Tree
    int maxHeight = findHeightUtil(root, x, h);
 
    // Return the height
    return h;
}
 
// Driver Code
int main()
{
    // Binary Tree Formation
    Node* root = newNode(5);
    root->left = newNode(10);
    root->right = newNode(15);
    root->left->left = newNode(20);
    root->left->right = newNode(25);
    root->left->right->right = newNode(45);
    root->right->left = newNode(30);
    root->right->right = newNode(35);
 
    int k = 25;
 
    // Function call to find the
    // depth of a given node
    cout << "Depth: "
         << findDepth(root, k) << "\n";
 
    // Function call to find the
    // height of a given node
    cout << "Height: " << findHeight(root, k);
 
    return 0;
}


Java
// Java program for the above approach
import java.util.*;
class GFG
{
 
static int height = -1;
 
// Structure of a Binary Tree Node
static class Node
{
    int data;
    Node left;
    Node right;
};
 
// Utility function to create
// a new Binary Tree Node
static Node newNode(int item)
{
    Node temp = new Node();
    temp.data = item;
    temp.left = temp.right = null;
    return temp;
}
 
// Function to find the depth of
// a given node in a Binary Tree
static int findDepth(Node root, int x)
{
     
    // Base case
    if (root == null)
        return -1;
 
    // Initialize distance as -1
    int dist = -1;
 
    // Check if x is current node=
    if ((root.data == x)||
     
        // Otherwise, check if x is
        // present in the left subtree
        (dist = findDepth(root.left, x)) >= 0 ||
         
        // Otherwise, check if x is
        // present in the right subtree
        (dist = findDepth(root.right, x)) >= 0)
 
        // Return depth of the node
        return dist + 1;
         
    return dist;
}
 
// Helper function to find the height
// of a given node in the binary tree
static int findHeightUtil(Node root, int x)
{
     
    // Base Case
    if (root == null)
    {
        return -1;
    }
 
    // Store the maximum height of
    // the left and right subtree
    int leftHeight = findHeightUtil(root.left, x);
 
    int rightHeight = findHeightUtil(root.right, x);
 
    // Update height of the current node
    int ans = Math.max(leftHeight, rightHeight) + 1;
 
    // If current node is the required node
    if (root.data == x)
        height = ans;
 
    return ans;
}
 
// Function to find the height of
// a given node in a Binary Tree
static int findHeight(Node root, int x)
{
     
    // Stores height of the Tree
    findHeightUtil(root, x);
 
    // Return the height
    return height;
}
 
// Driver Code
public static void main(String []args)
{
     
    // Binary Tree Formation
    Node root = newNode(5);
    root.left = newNode(10);
    root.right = newNode(15);
    root.left.left = newNode(20);
    root.left.right = newNode(25);
    root.left.right.right = newNode(45);
    root.right.left = newNode(30);
    root.right.right = newNode(35);
 
    int k = 25;
 
    // Function call to find the
    // depth of a given node
    System.out.println("Depth: " + findDepth(root, k));
 
    // Function call to find the
    // height of a given node
    System.out.println("Height: " + findHeight(root, k));
}
}
 
// This code is contributed by SURENDRA_GANGWAR


Python3
# Python3 program for the above approach
 
# Structure of a Binary Tree Node
class Node:
    def __init__(self, x):
        self.data = x
        self.left = None
        self.right = None
         
# Function to find the depth of
# a given node in a Binary Tree
def findDepth(root, x):
   
    # Base case
    if (root == None):
        return -1
 
    # Initialize distance as -1
    dist = -1
 
    # Check if x is current node=
    if (root.data == x):
        return dist + 1
 
    dist = findDepth(root.left, x)
    if dist >= 0:
        return dist + 1
    dist = findDepth(root.right, x)
    if dist >= 0:
        return dist + 1
    return dist
 
# Helper function to find the height
# of a given node in the binary tree
def findHeightUtil(root, x):
    global height
 
    # Base Case
    if (root == None):
        return -1
 
    # Store the maximum height of
    # the left and right subtree
    leftHeight = findHeightUtil(root.left, x)
 
    rightHeight = findHeightUtil(root.right, x)
 
    # Update height of the current node
    ans = max(leftHeight, rightHeight) + 1
 
    # If current node is the required node
    if (root.data == x):
        height = ans
 
    return ans
 
# Function to find the height of
# a given node in a Binary Tree
def findHeight(root, x):
    global height
 
    # Stores height of the Tree
    maxHeight = findHeightUtil(root, x)
 
    # Return the height
    return height
 
# Driver Code
if __name__ == '__main__':
   
    # Binary Tree Formation
    height = -1
    root = Node(5)
    root.left = Node(10)
    root.right = Node(15)
    root.left.left = Node(20)
    root.left.right = Node(25)
    root.left.right.right = Node(45)
    root.right.left = Node(30)
    root.right.right = Node(35)
 
    k = 25
 
    # Function call to find the
    # depth of a given node
    print("Depth: ",findDepth(root, k))
 
    # Function call to find the
    # height of a given node
    print("Height: ",findHeight(root, k))
 
    # This code is contributed by mohit kumar 29.


C#
// C# program for the above approach
using System;
using System.Collections.Generic;
 
class GFG{
 
static int height = -1;
 
// Structure of a Binary Tree Node
class Node
{
    public int data;
    public Node left;
    public Node right;
};
 
// Utility function to create
// a new Binary Tree Node
static Node newNode(int item)
{
    Node temp = new Node();
    temp.data = item;
    temp.left = temp.right = null;
    return temp;
}
 
// Function to find the depth of
// a given node in a Binary Tree
static int findDepth(Node root, int x)
{
     
    // Base case
    if (root == null)
        return -1;
 
    // Initialize distance as -1
    int dist = -1;
 
    // Check if x is current node=
    if ((root.data == x)||
     
        // Otherwise, check if x is
        // present in the left subtree
        (dist = findDepth(root.left, x)) >= 0 ||
         
        // Otherwise, check if x is
        // present in the right subtree
        (dist = findDepth(root.right, x)) >= 0)
 
        // Return depth of the node
        return dist + 1;
         
    return dist;
}
 
// Helper function to find the height
// of a given node in the binary tree
static int findHeightUtil(Node root, int x)
{
     
    // Base Case
    if (root == null)
    {
        return -1;
    }
 
    // Store the maximum height of
    // the left and right subtree
    int leftHeight = findHeightUtil(root.left, x);
 
    int rightHeight = findHeightUtil(root.right, x);
 
    // Update height of the current node
    int ans = Math.Max(leftHeight, rightHeight) + 1;
 
    // If current node is the required node
    if (root.data == x)
        height = ans;
 
    return ans;
}
 
// Function to find the height of
// a given node in a Binary Tree
static int findHeight(Node root, int x)
{
     
    // Stores height of the Tree
    findHeightUtil(root, x);
 
    // Return the height
    return height;
}
 
// Driver Code
public static void Main()
{
     
    // Binary Tree Formation
    Node root = newNode(5);
    root.left = newNode(10);
    root.right = newNode(15);
    root.left.left = newNode(20);
    root.left.right = newNode(25);
    root.left.right.right = newNode(45);
    root.right.left = newNode(30);
    root.right.right = newNode(35);
 
    int k = 25;
 
    // Function call to find the
    // depth of a given node
    Console.WriteLine("Depth: " + findDepth(root, k));
 
    // Function call to find the
    // height of a given node
    Console.WriteLine("Height: " + findHeight(root, k));
}
}
 
// This code is contributed by ipg2016107


输出:
Depth: 2
Height: 1

时间复杂度: O(N)
辅助空间: O(1)

如果您想与行业专家一起参加直播课程,请参阅Geeks Classes Live