在单向链表中查找最小和最大元素

给定一个包含 n 个节点的单向链表，并找出链表中最小和最大的元素。
例子：

Input : 15 14 13 22 17
Output : Linked list are:
        17 -> 22 -> 13 -> 14 -> 15 -> NULL
        Maximum element in linked list: 22
        Minimum element in linked list: 13

Input : 20 25 23 68 54 13 45
Output : Linked list are:
        45 -> 13 -> 54 -> 68 -> 23 -> 25 -> 20 -> NULL
        Maximum element in linked list: 68
        Minimum element in linked list: 13

这个想法是在 head 不等于 NULL 时遍历链表，并将max和min变量分别初始化为INT_MIN和INT_MAX 。之后检查一个条件，如果最大值小于则将头部值分配给最大值或最小值大于则将头部值分配给最小值，否则头部指向下一个节点。继续这个过程直到 head 不等于 NULL。

C++

// C++ Program to find smallest and largest
// elements in singly linked list.
#include 
 
using namespace std;
/* Linked list node */
struct Node {
    int data;
    struct Node* next;
};
 
// Function that returns the largest element
// from the linked list.
int largestElement(struct Node* head)
{
    // Declare a max variable and initialize
    // it with INT_MIN value.
    // INT_MIN is integer type and its value
    // is -32767 or less.
    int max = INT_MIN;
 
    // Check loop while head not equal to NULL
    while (head != NULL) {
 
        // If max is less then head->data then
        // assign value of head->data to max
        // otherwise node point to next node.
        if (max < head->data)
            max = head->data;
        head = head->next;
    }
    return max;
}
 
// Function that returns smallest element
// from the linked list.
int smallestElement(struct Node* head)
{
    // Declare a min variable and initialize
    // it with INT_MAX value.
    // INT_MAX is integer type and its value
    // is 32767 or greater.
    int min = INT_MAX;
 
    // Check loop while head not equal to NULL
    while (head != NULL) {
 
        // If min is greater then head->data then
        // assign value of head->data to min
        // otherwise node point to next node.
        if (min > head->data)
            min = head->data;
 
        head = head->next;
    }
    return min;
}
 
// Function that push the element in linked list.
void push(struct Node** head, int data)
{
    // Allocate dynamic memory for newNode.
    struct Node* newNode =
         (struct Node*)malloc(sizeof(struct Node));
 
    // Assign the data into newNode.
    newNode->data = data;
 
    // newNode->next assign the address of
    // head node.
    newNode->next = (*head);
 
    // newNode become the headNode.
    (*head) = newNode;
}
 
// Display linked list.
void printList(struct Node* head)
{
    while (head != NULL) {
        printf("%d -> ", head->data);
        head = head->next;
    }
    cout << "NULL" << endl;
}
 
// Driver program to test the functions
int main()
{
    // Start with empty list
    struct Node* head = NULL;
 
    // Using push() function to construct
    // singly linked list
    // 17->22->13->14->15
    push(&head, 15);
    push(&head, 14);
    push(&head, 13);
    push(&head, 22);
    push(&head, 17);
    cout << "Linked list is : " << endl;
 
    // Call printList() function to display
    // the linked list.
    printList(head);
    cout << "Maximum element in linked list:";
 
    // Call largestElement() function to get largest
    // element in linked list.
    cout << largestElement(head) << endl;
    cout << "Minimum element in linked list:";
 
    // Call smallestElement() function to get smallest
    // element in linked list.
    cout << smallestElement(head) << endl;
 
    return 0;
}

Java

// Java program to find smallest and largest
// elements in singly linked list.
class GfG
{
     
/* Linked list node */
static class Node
{
    int data;
    Node next;
}
static Node head = null;
 
// Function that returns the largest element
// from the linked list.
static int largestElement(Node head)
{
     
    // Declare a max variable and initialize
    // it with INT_MIN value.
    // INT_MIN is integer type and its value
    // is -32767 or less.
    int max = Integer.MIN_VALUE;
 
    // Check loop while head not equal to NULL
    while (head != null)
    {
 
        // If max is less then head->data then
        // assign value of head->data to max
        // otherwise node point to next node.
        if (max < head.data)
            max = head.data;
        head = head.next;
    }
    return max;
}
 
// Function that returns smallest element
// from the linked list.
static int smallestElement(Node head)
{
     
    // Declare a min variable and initialize
    // it with INT_MAX value.
    // INT_MAX is integer type and its value
    // is 32767 or greater.
    int min = Integer.MAX_VALUE;
 
    // Check loop while head not equal to NULL
    while (head != null)
    {
 
        // If min is greater then head->data then
        // assign value of head->data to min
        // otherwise node point to next node.
        if (min > head.data)
            min = head.data;
 
        head = head.next;
    }
    return min;
}
 
// Function that push the element in linked list.
static void push(int data)
{
    // Allocate dynamic memory for newNode.
    Node newNode = new Node();
 
    // Assign the data into newNode.
    newNode.data = data;
 
    // newNode->next assign the address of
    // head node.
    newNode.next = (head);
 
    // newNode become the headNode.
    (head) = newNode;
}
 
// Display linked list.
static void printList(Node head)
{
    while (head != null) {
        System.out.print(head.data + " -> ");
        head = head.next;
    }
    System.out.println("NULL");
}
 
// Driver  code
public static void main(String[] args)
{
    // Start with empty list
    // head = new Node();
 
    // Using push() function to construct
    // singly linked list
    // 17->22->13->14->15
    push( 15);
    push( 14);
    push( 13);
    push( 22);
    push( 17);
    System.out.println("Linked list is : ") ;
 
    // Call printList() function to 
    // display the linked list.
    printList(head);
    System.out.print("Maximum element in linked list: ");
 
    // Call largestElement() function to get
    // largest element in linked list.
    System.out.println(largestElement(head));
    System.out.print("Minimum element in linked list: ");
 
    // Call smallestElement() function to get 
    // smallest element in linked list.
    System.out.print(smallestElement(head));
}
}
 
// This code is contributed by Prerna saini.

Python

# Python3 program to find smallest and largest
# elements in singly linked list.
 
# Linked list node
class Node:
 
    def __init__(self):
        self.data = None
        self.next = None
 
head = None
 
# Function that returns the largest element
# from the linked list.
def largestElement(head):
 
    # Declare a max variable and initialize
    # it with INT_MIN value.
    # INT_MIN is integer type and its value
    # is -32767 or less.
    max = -32767
 
    # Check loop while head not equal to None
    while (head != None):
     
        # If max is less then head.data then
        # assign value of head.data to max
        # otherwise node point to next node.
        if (max < head.data) :
            max = head.data
        head = head.next
     
    return max
 
# Function that returns smallest element
# from the linked list.
def smallestElement(head):
 
    # Declare a min variable and initialize
    # it with INT_MAX value.
    # INT_MAX is integer type and its value
    # is 32767 or greater.
    min = 32767
 
    # Check loop while head not equal to None
    while (head != None) :
     
        # If min is greater then head.data then
        # assign value of head.data to min
        # otherwise node point to next node.
        if (min > head.data) :
            min = head.data
        head = head.next
     
    return min
 
# Function that push the element in linked list.
def push( data) :
 
    global head
 
    # Allocate dynamic memory for newNode.
    newNode = Node()
 
    # Assign the data into newNode.
    newNode.data = data
 
    # newNode.next assign the address of
    # head node.
    newNode.next = (head)
 
    # newNode become the headNode.
    (head) = newNode
 
# Display linked list.
def printList( head) :
 
    while (head != None) :
        print(head.data ,end= " -> ")
        head = head.next
     
    print("None")
 
# Driver code
 
# Start with empty list
# head = new Node()
 
# Using push() function to construct
# singly linked list
# 17.22.13.14.15
push( 15)
push( 14)
push( 13)
push( 22)
push( 17)
print("Linked list is : ")
 
# Call printList() function to
# display the linked list.
printList(head)
print("Maximum element in linked list: ",end="")
 
# Call largestElement() function to get
# largest element in linked list.
print(largestElement(head))
print("Minimum element in linked list: ",end="")
 
# Call smallestElement() function to get
# smallest element in linked list.
print(smallestElement(head),end="")
 
# This code is contributed by Arnab Kundu

C#

// C# program to find smallest and largest
// elements in singly linked list.
using System;
     
class GfG
{
 
    /* Linked list node */
    class Node
    {
        public int data;
        public Node next;
    }
    static Node head = null;
 
    // Function that returns the largest element
    // from the linked list.
    static int largestElement(Node head)
    {
 
        // Declare a max variable and initialize
        // it with INT_MIN value.
        // INT_MIN is integer type and its value
        // is -32767 or less.
        int max = int.MinValue;
 
        // Check loop while head not equal to NULL
        while (head != null)
        {
 
            // If max is less then head->data then
            // assign value of head->data to max
            // otherwise node point to next node.
            if (max < head.data)
                max = head.data;
            head = head.next;
        }
        return max;
    }
 
    // Function that returns smallest element
    // from the linked list.
    static int smallestElement(Node head)
    {
 
        // Declare a min variable and initialize
        // it with INT_MAX value.
        // INT_MAX is integer type and its value
        // is 32767 or greater.
        int min = int.MaxValue;
 
        // Check loop while head not equal to NULL
        while (head != null)
        {
 
            // If min is greater then head->data then
            // assign value of head->data to min
            // otherwise node point to next node.
            if (min > head.data)
                min = head.data;
 
            head = head.next;
        }
        return min;
    }
 
    // Function that push the element in linked list.
    static void push(int data)
    {
        // Allocate dynamic memory for newNode.
        Node newNode = new Node();
 
        // Assign the data into newNode.
        newNode.data = data;
 
        // newNode->next assign the address of
        // head node.
        newNode.next = (head);
 
        // newNode become the headNode.
        (head) = newNode;
    }
 
    // Display linked list.
    static void printList(Node head)
    {
        while (head != null)
        {
            Console.Write(head.data + " -> ");
            head = head.next;
        }
        Console.WriteLine("NULL");
    }
 
    // Driver code
    public static void Main()
    {
        // Start with empty list
        // head = new Node();
 
        // Using push() function to construct
        // singly linked list
        // 17->22->13->14->15
        push( 15);
        push( 14);
        push( 13);
        push( 22);
        push( 17);
        Console.WriteLine("Linked list is : ") ;
 
        // Call printList() function to
        // display the linked list.
        printList(head);
        Console.Write("Maximum element in linked list: ");
 
        // Call largestElement() function to get
        // largest element in linked list.
        Console.WriteLine(largestElement(head));
        Console.Write("Minimum element in linked list: ");
 
        // Call smallestElement() function to get
        // smallest element in linked list.
        Console.Write(smallestElement(head));
    }
}
 
// This code is contributed by PrinciRaj1992

Javascript

 
// JavaScript program to find smallest and largest
// elements in singly linked list.
    /* Linked list node */
    class Node {
        constructor(val) {
            this.data = val;
            this.next = null;
        }
    }
    var head = null;
 
    // Function that returns the largest element
    // from the linked list.
    function largestElement(head) {
 
        // Declare a max variable and initialize
        // it with INT_MIN value.
        // INT_MIN is integer type and its value
        // is -32767 or less.
        var max = Number.MIN_VALUE;
 
        // Check loop while head not equal to NULL
        while (head != null) {
 
            // If max is less then head->data then
            // assign value of head->data to max
            // otherwise node povar to next node.
            if (max < head.data)
                max = head.data;
            head = head.next;
        }
        return max;
    }
 
    // Function that returns smallest element
    // from the linked list.
    function smallestElement(head) {
 
        // Declare a min variable and initialize
        // it with INT_MAX value.
        // INT_MAX is integer type and its value
        // is 32767 or greater.
        var min = Number.MAX_VALUE;
 
        // Check loop while head not equal to NULL
        while (head != null) {
 
            // If min is greater then head->data then
            // assign value of head->data to min
            // otherwise node povar to next node.
            if (min > head.data)
                min = head.data;
 
            head = head.next;
        }
        return min;
    }
 
    // Function that push the element in linked list.
    function push(data) {
        // Allocate dynamic memory for newNode.
        var newNode = new Node();
 
        // Assign the data into newNode.
        newNode.data = data;
 
        // newNode->next assign the address of
        // head node.
        newNode.next = (head);
 
        // newNode become the headNode.
        (head) = newNode;
    }
 
    // Display linked list.
    function printList(head) {
        while (head != null) {
            document.write(head.data + " -> ");
            head = head.next;
        }
        document.write("NULL");
    }
 
    // Driver code
     
        // Start with empty list
        // head = new Node();
 
        // Using push() function to construct
        // singly linked list
        // 17->22->13->14->15
        push(15);
        push(14);
        push(13);
        push(22);
        push(17);
        document.write("Linked list is : <br/>");
 
        // Call printList() function to
        // display the linked list.
        printList(head);
        document.write("<br/>Maximum element in linked list: ");
 
        // Call largestElement() function to get
        // largest element in linked list.
        document.write(largestElement(head));
        document.write("<br/>Minimum element in linked list: ");
 
        // Call smallestElement() function to get
        // smallest element in linked list.
        document.write(smallestElement(head));
 
// This code contributed by Rajput-Ji
 

输出：

Linked list is :
17 -> 22 -> 13 -> 14 -> 15 -> NULL
Maximum element in linked list: 22
Minimum element in linked list: 13

如果您希望与专家一起参加现场课程，请参阅DSA 现场工作专业课程和学生竞争性编程现场课程。