用链表表示的两个数字相乘的 C++ 程序

给定两个由链表表示的数字，编写一个函数，返回这两个链表的乘积。

例子：

Input: 9->4->6
        8->4
Output: 79464

Input: 3->2->1
        1->2
Output: 3852

解决方案：
遍历两个列表并生成需要相乘的数字，然后返回两个数字的相乘值。
从链表表示生成数字的算法：

1) Initialize a variable to zero
2) Start traversing the linked list
3) Add the value of the first node to this variable
4) From the second node, multiply the variable by 10
   and also take the modulus of this value by 10^9+7
   and then add the value of the node to this 
   variable.
5) Repeat step 4 until we reach the last node of the list. 

将上述算法与两个链表一起使用以生成数字。

下面是用链表表示的两个数字相乘的程序：

C++

// C++ program to Multiply two numbers
// represented as linked lists
#include
#include
using namespace std;
    
// Linked list node
struct Node
{
    int data;
    struct Node* next;
};
    
// Function to create a new node 
// with given data
struct Node *newNode(int data)
{
    struct Node *new_node = 
           (struct Node *) malloc(sizeof(struct Node));
    new_node->data = data;
    new_node->next = NULL;
    return new_node;
}
    
// 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 = 
           newNode(new_data);
    
    // Link the old list off the 
    // new node 
    new_node->next = (*head_ref);
    
    // Move the head to point to the 
    // new node 
    (*head_ref) = new_node;
}
    
// Multiply contents of two linked lists
long long multiplyTwoLists (Node* first, 
                            Node* second)
{
    long long N= 1000000007;
    long long num1 = 0, num2 = 0;
    while (first || second)
    {        
        if(first)
        {
            num1 = (((num1) * 10) % N + 
                      first -> data);
            first = first -> next;
        }
          
        if(second)
        {
            num2 = (((num2) * 10) % N + 
                      second -> data);
            second = second->next;
        }
          
    }
    return (((num1 % N) * 
             (num2 % N)) % N);
}
    
// A utility function to print a 
// linked list
void printList(struct Node *node)
{
    while(node != NULL)
    {
        cout << node -> data;
        if(node -> next)
            cout << "->";
        node = node -> next;
    }
    cout << "";
}
    
// Driver code
int main()
{
    struct Node* first = NULL;
    struct Node* second = NULL;
    
    // Create first list 9->4->6
    push(&first, 6);
    push(&first, 4);
    push(&first, 9);
    printf("First List is: ");
    printList(first);
    
    // Create second list 8->4
    push(&second, 4);
    push(&second, 8);
    printf("Second List is: ");
    printList(second);
    
    // Multiply the two lists and see result
    cout << "Result is: ";
    cout << multiplyTwoLists(first, 
                             second);  
    return 0;
}

输出：

First List is: 9->4->6
Second List is: 8->4
Result is: 79464

有关详细信息，请参阅有关将链接列表表示的两个数字相乘的完整文章！