p182.java

/*Given elements as nodes of the two linked lists. The task is to multiply these two linked lists, say L1 and L2. 

Note: The output could be large take modulo 109+7.

Example:

Input:
2
2
3 2
1
2
3
1 0 0
2
1 0 
Output:
64
1000

Explanation:
Testcase 1: 32*2 = 64.
Testcase 2: 100*10 = 1000.
Input:
The first line of input contains an integer T denoting the number of test cases. Then T test cases follow, the first line of each test case contains an integer N denoting the size of the first linked list (L1). In the next line are the space-separated values of the first linked list. The third line of each test case contains an integer M denoting the size of the second linked list (L2). In the fourth line is space-separated values of the second linked list.

Output:
For each test case output will be an integer denoting the product of the two linked lists.

Your Task:
The task is to complete the function multiplyTwoLists() which should multiply the given two linked lists and return the result.

Constraints:
1 <= T <= 100
1 <= N, M <= 100*/
 
/* Node is defined as
class Node{
    int data; 
    Node next;
    Node(int data) {
        this.data=data;
        this.next = null;
    }
}*/

class GfG {
    public long multiplyTwoLists(Node l1, Node l2) {
        long num1 = 0;
        long num2 = 0;
        long mod=1000000007; // To prevent overflow
        while (l1 != null || l2 != null) {
            if (l1 != null) {
                num1 = (num1 * 10 + l1.data)%mod;
                l1 = l1.next;
            }
            if (l2 != null) {
                num2 = (num2 * 10 + l2.data)%mod;
                l2 = l2.next;
            }
        }
        return (num1 * num2)%mod;
    }
}