CODEWITHSUNDEEP
javabigintegerfactorial
waynekenoff
waynekenoff

Reputation: 47

Shows specific digit of the output // deleting 0's from bigInteger

How could I show only specific digit of an output? How could I delete 0's from a bigInteger?

My Example:

Having a task to show number's factorial's last number that isn't 0.

Example:
1! = 1
2! = 2
3! = 6
4! = 4
5! = 2
6! = 2

Right now it just shows factorial.

import java.math.BigInteger;
import java.util.Scanner;

public class Main{
    // Returns Factorial of N
    static BigInteger factorial(int N){
        // Initialize result
        BigInteger f = new BigInteger("1"); // Or BigInteger.ONE

        // Multiply f with 2, 3, ...N
        for (int i = 2; i <= N; i++)
            f = f.multiply(BigInteger.valueOf(i));

        return f;
    }

    // Driver method
    public static void main(String args[]) throws Exception
    {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        System.out.println(factorial(n));
    }
}

Example vol2 --> Here I need a solution to remove 0's from biginteger:

import java.math.BigInteger;
import java.util.Scanner;

public class Main{
    // Returns Factorial of N
    static BigInteger factorial(int N){
        // Initialize result
        BigInteger f = new BigInteger("1"); // Or BigInteger.ONE

        // Multiply f with 2, 3, ...N
        for (int i = 2; i <= N; i++)
            f = f.multiply(BigInteger.valueOf(i));

        return f;
    }

    // Driver method
    public static void main(String args[]) throws Exception
    {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        BigInteger a = (factorial(n));
        BigInteger b, c;
        c = new BigInteger("10");
        b = a.mod(c);
        System.out.println(b);
        System.out.println(a);
    }
}

Is there an easy way to remove all 0's from a number? That would be the easiest way to fix my problem

Upvotes: 2

Views: 172

Answers (1)

Christian
Christian

Reputation: 22343

You could just convert your number into a string and remove the zeros. Then you put it back into BigInteger:

public static BigInteger removeZeroes(int i) {
    return new BigInteger(String.valueOf(i).replace("0", ""));
}

Upvotes: 5

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