Question

This is java. Please let me know about those code.
Please do not use array and scanner. Just do by loop.
// a) Task: Find the sum of all multiples of 3 and 5 less than 1000.
        // b) Task: Given two integers k and n, print out every multiple of k less than n
        // c) Task: Given an integer n, print out k^k for every k=1...n
        // d) Task: Write a function called "factorProduct" that takes as input a whole number "n", and returns the product of all numbers that divide n (excluding n).

Answer 1

Task a:

import java.io.*;

class GFG {
   public static void main (String[] args) {
       int i,j,sum=0;
       for(i=3;i<1000;i=i+3) //multiples of 3
       sum+=i;
       for(j=5;j<1000;j=j+5) //multiples of 5
       sum+=j;
       System.out.println("Sum of all multiples of 3 and 5 less than 1000 is "+sum);
   }
}

Output:

Task b:

import java.io.*;
import java.util.*;

class GFG {
   public static void main (String[] args) {
       int k,n;
       Scanner sc = new Scanner(System.in);
       System.out.println("Enter the values of k and n:");
       k=sc.nextInt();
       n=sc.nextInt();
       System.out.println("Multiples of "+k+" less than "+n+":");
       for(int i=k;i<n;i=i+k)
       System.out.println(i);
   }
}

Output:

Task c:

import java.io.*;
import java.util.*;
import java.lang.Math;

class GFG {
   public static void main (String[] args) {
       int n;
       Scanner sc = new Scanner(System.in);
       System.out.println("Enter the value n:");
       n=sc.nextInt();
       for(int i=1;i<=n;i++)
       System.out.println(i+"^"+i+"= "+Math.pow(i, i));
   }
}

Output:

Task d:

import java.io.*;
import java.util.*;

class GFG {
public static int factorProduct(int n){
int product = 1;
for(int i=2;i<n;i++){
if(n%i==0)
product*=i;
}
return product;
}
   public static void main (String[] args) {
       int n;
       Scanner sc = new Scanner(System.in);
       System.out.println("Enter the value n:");
       n=sc.nextInt();
       System.out.println("Product of all factors of "+n+" is "+factorProduct(n));
   }
}

Output: