📜  从2D矩阵构造双链链表

📅  最后修改于: 2021-05-24 20:32:03             🧑  作者: Mango

给定2D矩阵,任务是将其转换为带有下一个,上一个,上和下四个指针的双向链接列表,此列表的每个节点应连接到其下一个,上一个,上和下节点。
例子:

Input: 2D matrix 
1 2 3
4 5 6
7 8 9
Output:

方法:主要思想是为矩阵的每个元素构造一个新节点,然后递归地创建它的上,下,上一个和下一个节点,并分别更改上一个和上一个指针的指针。
下面是上述方法的实现:

C++
// C++ programm to construct a Doubly
// linked linked list from 2D Matrix
 
#include 
using namespace std;
 
// define dimension of matrix
#define dim 3
 
// struct node of doubly linked
// list with four pointer
// next, prev, up, down
struct Node {
    int data;
    Node* next;
    Node* prev;
    Node* up;
    Node* down;
};
 
// function to create a new node
Node* createNode(int data)
{
    Node* temp = new Node();
    temp->data = data;
    temp->next = NULL;
    temp->prev = NULL;
    temp->up = NULL;
    temp->down = NULL;
    return temp;
}
 
// function to construct the
// doubly linked list
Node* constructDoublyListUtil(
    int mtrx[][dim],
    int i, int j,
    Node* curr)
{
 
    if (i >= dim || j >= dim) {
        return NULL;
    }
 
    // Create Node with value contain
    // in matrix at index (i, j)
    Node* temp = createNode(mtrx[i][j]);
 
    // Assign address of curr into
    // the prev pointer of temp
    temp->prev = curr;
 
    // Assign address of curr into
    // the up pointer of temp
    temp->up = curr;
 
    // Recursive call for next pointer
    temp->next
        = constructDoublyListUtil(
            mtrx, i, j + 1, temp);
 
    // Recursive call for down pointer
    temp->down
        = constructDoublyListUtil(
            mtrx, i + 1, j, temp);
 
    // Return newly constructed node
    // whose all four node connected
    // at it's appropriate position
    return temp;
}
 
// Function to construct the doubly linked list
Node* constructDoublyList(int mtrx[][dim])
{
    // function call for construct
    // the doubly linked list
    return constructDoublyListUtil(
        mtrx, 0, 0, NULL);
}
 
// function for displaying
// doubly linked list data
void display(Node* head)
{
    // pointer to move right
    Node* rPtr;
 
    // pointer to move down
    Node* dPtr = head;
 
    // loop till node->down is not NULL
    while (dPtr) {
 
        rPtr = dPtr;
 
        // loop till node->right is not NULL
        while (rPtr) {
            cout << rPtr->data << " ";
            rPtr = rPtr->next;
        }
 
        cout << "\n";
        dPtr = dPtr->down;
    }
}
 
// driver code
int main()
{
 
    // initialise matrix
    int mtrx[dim][dim] = {
        { 1, 2, 3 },
        { 4, 5, 6 },
        { 7, 8, 9 }
    };
 
    Node* list = constructDoublyList(mtrx);
 
    display(list);
 
    return 0;
}


Java
// Java program to construct a Doubly
// linked linked list from 2D Matrix
import java.util.*;
 
class GFG{
    // define dimension of matrix
    static int dim= 3;
     
    // struct node of doubly linked
    // list with four pointer
    // next, prev, up, down
    static class Node {
        int data;
        Node next;
        Node prev;
        Node up;
        Node down;
    };
     
    // function to create a new node
    static Node createNode(int data)
    {
        Node temp = new Node();
        temp.data = data;
        temp.next = null;
        temp.prev = null;
        temp.up = null;
        temp.down = null;
        return temp;
    }
     
    // function to construct the
    // doubly linked list
    static Node constructDoublyListUtil(int mtrx[][],int i, int j,Node curr)
    {
     
        if (i >= dim || j >= dim) {
            return null;
        }
     
        // Create Node with value contain
        // in matrix at index (i, j)
        Node temp = createNode(mtrx[i][j]);
     
        // Assign address of curr into
        // the prev pointer of temp
        temp.prev = curr;
     
        // Assign address of curr into
        // the up pointer of temp
        temp.up = curr;
     
        // Recursive call for next pointer
        temp.next
            = constructDoublyListUtil(mtrx, i, j + 1, temp);
     
        // Recursive call for down pointer
        temp.down= constructDoublyListUtil(mtrx, i + 1, j, temp);
     
        // Return newly constructed node
        // whose all four node connected
        // at it's appropriate position
        return temp;
    }
     
    // Function to construct the doubly linked list
    static Node constructDoublyList(int mtrx[][])
    {
        // function call for construct
        // the doubly linked list
        return constructDoublyListUtil(mtrx, 0, 0, null);
    }
     
    // function for displaying
    // doubly linked list data
    static void display(Node head)
    {
        // pointer to move right
        Node rPtr;
     
        // pointer to move down
        Node dPtr = head;
     
        // loop till node.down is not null
        while (dPtr != null) {
     
            rPtr = dPtr;
     
            // loop till node.right is not null
            while (rPtr!=null) {
                System.out.print(rPtr.data+" ");
                rPtr = rPtr.next;
            }
     
            System.out.print("\n");
            dPtr = dPtr.down;
        }
    }
     
    // driver code
    public static void main(String args[])
    {
     
        // initialise matrix
        int mtrx[][] = {
            { 1, 2, 3 },
            { 4, 5, 6 },
            { 7, 8, 9 }
        };
     
        Node list = constructDoublyList(mtrx);
     
        display(list);
     
    }
}
 
// This code is contributed by AbhiThakur


Python3
# Python3 programm to construct
# a Doubly linked linked list
# from 2D Matrix
  
# define dimension of matrix
dim = 3
  
# struct node of doubly linked
# list with four pointer
# next, prev, up, down
class Node:
     
    def __init__(self, data):
       
        self.data = data
        self.prev = None
        self.up = None
        self.down = None
        self.next = None       
         
# function to create a
# new node
def createNode(data):
 
    temp = Node(data);   
    return temp;
  
# function to construct the
# doubly linked list
def constructDoublyListUtil(mtrx, i,
                            j, curr):
  
    if (i >= dim or
        j >= dim):
        return None;
      
    # Create Node with value
    # contain in matrix at
    # index (i, j)
    temp = createNode(mtrx[i][j]);
  
    # Assign address of curr into
    # the prev pointer of temp
    temp.prev = curr;
  
    # Assign address of curr into
    # the up pointer of temp
    temp.up = curr;
  
    # Recursive call for next
    # pointer
    temp.next= constructDoublyListUtil(mtrx, i,
                                       j + 1,
                                       temp);
  
    # Recursive call for down pointer
    temp.down= constructDoublyListUtil(mtrx,
                                       i + 1,
                                       j, temp);
  
    # Return newly constructed node
    # whose all four node connected
    # at it's appropriate position
    return temp;
 
# Function to construct the
# doubly linked list
def constructDoublyList(mtrx):
 
    # function call for construct
    # the doubly linked list
    return constructDoublyListUtil(mtrx,
                                   0, 0,
                                   None);
   
# function for displaying
# doubly linked list data
def display(head):
 
    # pointer to move right
    rPtr = None
  
    # pointer to move down
    dPtr = head;
  
    # loop till node->down
    # is not NULL
    while (dPtr != None):
  
        rPtr = dPtr;
  
        # loop till node->right
        # is not NULL
        while (rPtr != None):
            print(rPtr.data,
                  end = ' ')
            rPtr = rPtr.next;
         
        print()
        dPtr = dPtr.down;
     
# Driver code
if __name__=="__main__":
     
    # initialise matrix
    mtrx =[[1, 2, 3],
           [4, 5, 6],
           [7, 8, 9]]
  
    list = constructDoublyList(mtrx);
    display(list);
 
# This code is contributed by Rutvik_56


C#
// C# program to construct a Doubly
// linked linked list from 2D Matrix
using System;
 
class GFG{
    // define dimension of matrix
    static int dim= 3;
     
    // struct node of doubly linked
    // list with four pointer
    // next, prev, up, down
    public class Node {
        public int data;
        public Node next, prev, up, down;
    };
     
    // function to create a new node
    static Node createNode(int data)
    {
        Node temp = new Node();
        temp.data = data;
        temp.next = null;
        temp.prev = null;
        temp.up = null;
        temp.down = null;
        return temp;
    }
     
    // function to construct the
    // doubly linked list
    static Node constructDoublyListUtil(int[,] mtrx,int i, int j,Node curr)
    {
     
        if (i >= dim || j >= dim) {
            return null;
        }
     
        // Create Node with value contain
        // in matrix at index (i, j)
        Node temp = createNode(mtrx[i,j]);
     
        // Assign address of curr into
        // the prev pointer of temp
        temp.prev = curr;
     
        // Assign address of curr into
        // the up pointer of temp
        temp.up = curr;
     
        // Recursive call for next pointer
        temp.next
            = constructDoublyListUtil(mtrx, i, j + 1, temp);
     
        // Recursive call for down pointer
        temp.down= constructDoublyListUtil(mtrx, i + 1, j, temp);
     
        // Return newly constructed node
        // whose all four node connected
        // at it's appropriate position
        return temp;
    }
     
    // Function to construct the doubly linked list
    static Node constructDoublyList(int[,] mtrx)
    {
        // function call for construct
        // the doubly linked list
        return constructDoublyListUtil(mtrx, 0, 0, null);
    }
     
    // function for displaying
    // doubly linked list data
    static void display(Node head)
    {
        // pointer to move right
        Node rPtr;
     
        // pointer to move down
        Node dPtr = head;
     
        // loop till node.down is not null
        while (dPtr != null) {
     
            rPtr = dPtr;
     
            // loop till node.right is not null
            while (rPtr!=null) {
                Console.Write(rPtr.data+" ");
                rPtr = rPtr.next;
            }
     
            Console.Write("\n");
            dPtr = dPtr.down;
        }
    }
     
    // driver code
    public static void Main()
    {
     
        // initialise matrix
        int[,] mtrx = {
            { 1, 2, 3 },
            { 4, 5, 6 },
            { 7, 8, 9 }
        };
     
        Node list = constructDoublyList(mtrx);
     
        display(list);
     
    }
}
 
// This code is contributed by AbhiThakur


输出:
1 2 3 
4 5 6 
7 8 9