查找链表中所有节点的平均值的程序

给定一个单链表。任务是找到给定单链表的所有节点的平均值。
例子：

Input: 7->6->8->4->1
Output: 26
Average of nodes:
(7 + 6 + 8 + 4 + 1 ) / 5 = 5.2

Input: 1->7->3->9->11->5
Output: 6

迭代解决方案：

1. 用链表的头部初始化一个指针 ptr，用 0 初始化一个 sum 变量。
2. 使用循环开始遍历链表，直到遍历完所有节点。
3. 将当前节点的值添加到总和中，即 sum += ptr -> data 。
4. 增加指向链表下一个节点的指针，即 ptr = ptr ->next 。
5. 将总和除以节点总数并返回平均值。

下面是上述方法的实现：

C++

// C++ implementation to find the average of
// nodes of the Linked List
  
#include 
using namespace std;
  
/* A Linked list node */
struct Node {
    int data;
    struct Node* next;
};
  
// function to insert a node at the
// beginning of the linked list
void push(struct Node** head_ref, int new_data)
{
    /* allocate node */
    struct Node* new_node = new Node;
  
    /* put in the data */
    new_node->data = new_data;
  
    /* link the old list to the new node */
    new_node->next = (*head_ref);
  
    /* move the head to point to the new node */
    (*head_ref) = new_node;
}
  
// Function to iteratively find the avg of
// nodes of the given linked list
float avgOfNodes(struct Node* head)
{
    // if head = NULL
    if (!head)
        return -1;
  
    int count = 0; // Initialize count
    int sum = 0;
    float avg = 0.0;
  
    struct Node* current = head; // Initialize current
    while (current != NULL) {
        count++;
        sum += current->data;
        current = current->next;
    }
  
    // calculate average
    avg = (double)sum / count;
  
    return avg;
}
  
// Driver Code
int main()
{
    struct Node* head = NULL;
  
    // create linked list 7->6->8->4->1
    push(&head, 7);
    push(&head, 6);
    push(&head, 8);
    push(&head, 4);
    push(&head, 1);
  
    cout << "Average of nodes = " << avgOfNodes(head);
  
    return 0;
}

Java

// Java implementation to find the average of
// nodes of the Linked List
class GFG
{ 
      
/* A Linked list node */
static class Node 
{
    int data;
    Node next;
};
  
// function to insert a node at the
// beginning of the linked list
static Node push(Node head_ref, int new_data)
{
    /* allocate node */
    Node new_node = new Node();
  
    /* put in the data */
    new_node.data = new_data;
  
    /* link the old list to the new node */
    new_node.next = (head_ref);
  
    /* move the head to point to the new node */
    (head_ref) = new_node;
    return head_ref;
}
  
// Function to iteratively find the avg of
// nodes of the given linked list
static double avgOfNodes(Node head)
{
    // if head = null
    if (head == null)
        return -1;
  
    int count = 0; // Initialize count
    int sum = 0;
    double avg = 0.0;
  
    Node current = head; // Initialize current
    while (current != null)
    {
        count++;
        sum += current.data;
        current = current.next;
    }
  
    // calculate average
    avg = (double)sum / count;
  
    return avg;
}
  
// Driver Code
public static void main(String args[])
{
    Node head = null;
  
    // create linked list 7.6.8.4.1
    head=push(head, 7);
    head=push(head, 6);
    head=push(head, 8);
    head=push(head, 4);
    head=push(head, 1);
  
    System.out.println("Average of nodes = " + avgOfNodes(head));
}
}
// This code is contributed by Arnab Kundu

Python3

# Python3 implementation to find the average of 
# nodes of the Linked List 
class newNode: 
  
    # Constructor to create a new node 
    def __init__(self, data): 
        self.data = data 
        self.next = None
  
# function to insert a node at the 
# beginning of the linked list 
def push(node,data):
      
    ''' allocate node '''
    if (node == None): 
        return (newNode(data)) 
      
    else:
        node.next = push(node.next, data) 
        return node 
  
# Function to iteratively find the avg of 
# nodes of the given linked list 
def avgOfNodes(head):
      
    # if head = NULL 
    if (head == None):
        return -1
      
    count = 0 # Initialize count 
    sum = 0
    avg = 0.0
  
    while (head != None):
        count += 1
        sum += head.data 
        head = head.next
      
    # calculate average 
    avg = sum / count 
    return avg 
  
# Driver Code 
  
# create linked list 7.6.8.4.1 
head = newNode(7) 
push(head, 6) 
push(head, 8) 
push(head, 4) 
push(head, 1) 
print("Average of nodes = ",avgOfNodes(head))
  
# This code is contributed by
# Shubham Singh(SHUBHAMSINGH10)

C#

// C# implementation to find the average 
// of nodes of the Linked List 
using System;
  
class GFG 
{ 
      
/* A Linked list node */
public class Node 
{ 
    public int data; 
    public Node next; 
}; 
  
// function to insert a node at the 
// beginning of the linked list 
static Node push(Node head_ref, 
                 int new_data) 
{ 
    /* allocate node */
    Node new_node = new Node(); 
  
    /* put in the data */
    new_node.data = new_data; 
  
    /* link the old list to the new node */
    new_node.next = (head_ref); 
  
    /* move the head to point to the new node */
    (head_ref) = new_node; 
    return head_ref; 
} 
  
// Function to iteratively find the avg of 
// nodes of the given linked list 
static double avgOfNodes(Node head) 
{ 
    // if head = null 
    if (head == null) 
        return -1; 
  
    int count = 0; // Initialize count 
    int sum = 0; 
    double avg = 0.0; 
  
    Node current = head; // Initialize current 
    while (current != null) 
    { 
        count++; 
        sum += current.data; 
        current = current.next; 
    } 
  
    // calculate average 
    avg = (double)sum / count; 
  
    return avg; 
} 
  
// Driver Code 
public static void Main(String []args) 
{ 
    Node head = null; 
  
    // create linked list 7.6.8.4.1 
    head=push(head, 7); 
    head=push(head, 6); 
    head=push(head, 8); 
    head=push(head, 4); 
    head=push(head, 1); 
  
    Console.WriteLine("Average of nodes = " + 
                           avgOfNodes(head)); 
} 
} 
  
// This code is contributed by Rajput-Ji

Javascript

// javascript implementation to find the average of
// nodes of the Linked List    /* A Linked list node */
class Node {
    constructor(val) {
        this.data = val;
        this.next = null;
    }
}
  
    // function to insert a node at the
    // beginning of the linked list
    function push(head_ref , new_data) {
        /* allocate node */
var new_node = new Node();
  
        /* put in the data */
        new_node.data = new_data;
  
        /* link the old list to the new node */
        new_node.next = (head_ref);
  
        /* move the head to point to the new node */
        (head_ref) = new_node;
        return head_ref;
    }
  
    // Function to iteratively find the avg of
    // nodes of the given linked list
    function avgOfNodes(head) {
        // if head = null
        if (head == null)
            return -1;
  
        var count = 0; // Initialize count
        var sum = 0;
        var avg = 0.0;
  
var current = head; // Initialize current
        while (current != null) {
            count++;
            sum += current.data;
            current = current.next;
        }
  
        // calculate average
        avg =  sum / count;
  
        return avg;
    }
  
    // Driver Code
      
var head = null;
  
        // create linked list 7.6.8.4.1
        head = push(head, 7);
        head = push(head, 6);
        head = push(head, 8);
        head = push(head, 4);
        head = push(head, 1);
  
        document.write("Average of nodes = " + avgOfNodes(head));
  
// This code contributed by aashish1995

输出：

Average of nodes = 5.2

时间复杂度： O(n)
其中 n 等于节点数。