先决条件 : 双链表 , 循环链表 , 循环双链表 给定N个元素的数组。任务是编写一个程序，将数组转换为 循环双链表 .
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其思想是开始遍历数组，为每个数组元素创建一个新的列表节点，并分配 上 和 下一个 相应地，该节点的指针。
- 创建一个指针 开始 指向列表的开头，该列表最初将指向NULL（空列表）。
- 对于数组的第一个元素，创建一个新节点，并将该节点的 上 和 下一个 指针指向指向开始以保持列表的循环方式。
- 对于其余的数组元素，将这些元素插入到创建的循环双链接列表的末尾。
以下是上述理念的实施：
C++
// CPP program to convert array to // circular doubly linked list #include<bits/stdc++.h> using namespace std; // Doubly linked list node struct node { int data; struct node *next; struct node *prev; }; // Utility function to create a node in memory struct node* getNode() { return (( struct node *) malloc ( sizeof ( struct node))); } // Function to display the list int displayList( struct node *temp) { struct node *t = temp; if (temp == NULL) return 0; else { cout<< "The list is: " ; while (temp->next != t) { cout<<temp->data<< " " ; temp = temp->next; } cout<<temp->data; return 1; } } // Function to convert array into list void createList( int arr[], int n, struct node **start) { // Declare newNode and temporary pointer struct node *newNode,*temp; int i; // Iterate the loop until array length for (i=0;i<n;i++) { // Create new node newNode = getNode(); // Assign the array data newNode->data = arr[i]; // If it is first element // Put that node prev and next as start // as it is circular if (i==0) { *start = newNode; newNode->prev = *start; newNode->next = *start; } else { // Find the last node temp = (*start)->prev; // Add the last node to make them // in circular fashion temp->next = newNode; newNode->next = *start; newNode->prev = temp; temp = *start; temp->prev = newNode; } } } // Driver Code int main() { // Array to be converted int arr[] = {1,2,3,4,5}; int n = sizeof (arr) / sizeof (arr[0]); // Start Pointer struct node *start = NULL; // Create the List createList(arr, n, &start); // Display the list displayList(start); return 0; } |
JAVA
// Java program to convert array to // circular doubly linked list class GFG { // Doubly linked list node static class node { int data; node next; node prev; }; // Utility function to create a node in memory static node getNode() { return new node(); } // Function to display the list static int displayList( node temp) { node t = temp; if (temp == null ) return 0 ; else { System.out.print( "The list is: " ); while (temp.next != t) { System.out.print(temp.data+ " " ); temp = temp.next; } System.out.print(temp.data); return 1 ; } } // Function to convert array into list static node createList( int arr[], int n, node start) { // Declare newNode and temporary pointer node newNode,temp; int i; // Iterate the loop until array length for (i = 0 ; i < n; i++) { // Create new node newNode = getNode(); // Assign the array data newNode.data = arr[i]; // If it is first element // Put that node prev and next as start // as it is circular if (i == 0 ) { start = newNode; newNode.prev = start; newNode.next = start; } else { // Find the last node temp = (start).prev; // Add the last node to make them // in circular fashion temp.next = newNode; newNode.next = start; newNode.prev = temp; temp = start; temp.prev = newNode; } } return start; } // Driver Code public static void main(String args[]) { // Array to be converted int arr[] = { 1 , 2 , 3 , 4 , 5 }; int n = arr.length; // Start Pointer node start = null ; // Create the List start = createList(arr, n, start); // Display the list displayList(start); } } // This code is contributed by Arnab Kundu |
Python3
# Python3 program to convert array to # circular doubly linked list # Node of the doubly linked list class Node: def __init__( self , data): self .data = data self .prev = None self . next = None # Utility function to create a node in memory def getNode(): return (Node( 0 )) # Function to display the list def displayList(temp): t = temp if (temp = = None ): return 0 else : print ( "The list is: " , end = " " ) while (temp. next ! = t): print (temp.data, end = " " ) temp = temp. next print (temp.data) return 1 # Function to convert array into list def createList(arr, n, start): # Declare newNode and temporary pointer newNode = None temp = None i = 0 # Iterate the loop until array length while (i < n): # Create new node newNode = getNode() # Assign the array data newNode.data = arr[i] # If it is first element # Put that node prev and next as start # as it is circular if (i = = 0 ): start = newNode newNode.prev = start newNode. next = start else : # Find the last node temp = (start).prev # Add the last node to make them # in circular fashion temp. next = newNode newNode. next = start newNode.prev = temp temp = start temp.prev = newNode i = i + 1 return start # Driver Code if __name__ = = "__main__" : # Array to be converted arr = [ 1 , 2 , 3 , 4 , 5 ] n = len (arr) # Start Pointer start = None # Create the List start = createList(arr, n, start) # Display the list displayList(start) # This code is contributed by Arnab Kundu |
C#
// C# program to convert array to // circular doubly linked list using System; class GFG { // Doubly linked list node public class node { public int data; public node next; public node prev; }; // Utility function to create a node in memory static node getNode() { return new node(); } // Function to display the list static int displayList( node temp) { node t = temp; if (temp == null ) return 0; else { Console.Write( "The list is: " ); while (temp.next != t) { Console.Write(temp.data + " " ); temp = temp.next; } Console.Write(temp.data); return 1; } } // Function to convert array into list static node createList( int []arr, int n, node start) { // Declare newNode and temporary pointer node newNode,temp; int i; // Iterate the loop until array length for (i = 0; i < n; i++) { // Create new node newNode = getNode(); // Assign the array data newNode.data = arr[i]; // If it is first element // Put that node prev and next as start // as it is circular if (i == 0) { start = newNode; newNode.prev = start; newNode.next = start; } else { // Find the last node temp = (start).prev; // Add the last node to make them // in circular fashion temp.next = newNode; newNode.next = start; newNode.prev = temp; temp = start; temp.prev = newNode; } } return start; } // Driver Code public static void Main(String []args) { // Array to be converted int []arr = {1,2,3,4,5}; int n = arr.Length; // Start Pointer node start = null ; // Create the List start = createList(arr, n, start); // Display the list displayList(start); } } // This code contributed by Rajput-Ji |
Javascript
<script> // JavaScript program to convert array to // circular doubly linked list // Doubly linked list node class node { constructor() { this .data=0; this .next= this .prev= null ; } } // Utility function to create a node in memory function getNode() { return new node(); } // Function to display the list function displayList(temp) { let t = temp; if (temp == null ) return 0; else { document.write( "The list is: " ); while (temp.next != t) { document.write(temp.data+ " " ); temp = temp.next; } document.write(temp.data); return 1; } } // Function to convert array into list function createList(arr,n,start) { // Declare newNode and temporary pointer let newNode,temp; let i; // Iterate the loop until array length for (i = 0; i < n; i++) { // Create new node newNode = getNode(); // Assign the array data newNode.data = arr[i]; // If it is first element // Put that node prev and next as start // as it is circular if (i == 0) { start = newNode; newNode.prev = start; newNode.next = start; } else { // Find the last node temp = (start).prev; // Add the last node to make them // in circular fashion temp.next = newNode; newNode.next = start; newNode.prev = temp; temp = start; temp.prev = newNode; } } return start; } // Driver Code let arr=[1,2,3,4,5]; let n = arr.length; // Start Pointer let start = null ; // Create the List start = createList(arr, n, start); // Display the list displayList(start); // This code is contributed by avanitrachhadiya2155 </script> |
输出：
The list is: 1 2 3 4 5
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