Java Program to Generate N Number of Passwords of Length M Each

Java program to generate N number of passwords each of length M. The number of passwords returned doesn’t exceed the length M.

Example:

Input : N = 1, M = 3
Output: 571

Input : N = 2, M = 4
Output: 5671
        1987

Approach:

• Import random package for creating random numbers.
• Initialize variables N and M.
• Create an array of N length.
• Run nested loops

1. First loop for generating N numbers of passwords.
2. Second loop for creating the password of M length.

Below is the implementation of the above approach:

Java

// Java Program to Generate N Number
// of Passwords of Length M Each
import java.util.Random;
import java.util.Scanner;

public class GFG {
    public static void main(String args[])
    {
        // create a object of random class
        Random r = new Random();
        // N is numbers of password
        int N = 5;
        // M is the length of passwords
        int M = 8;
        // create a array of store passwords
        int[] a = new int[N];

        // run for loop N time
        for (int j = 0; j < N; j++) {
            // run this loop M time for generating
            // M length password
            for (int i = 0; i < M; i++) {
                // store the password in array
                System.out.print(a[j] = r.nextInt(10));
            }
            System.out.println();
        }
    }
}

Output

73807243
05081188
63921767
70426689
06272980

Time Complexity: O(N*M), where N is the number of passwords required and M is the length of each password.

Auxiliary Space: O(N) as using extra space for array a of size N