DSA-Java/functions.java at main · Shikhartiwari967/DSA-Java · GitHub

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 import java.util.*;
public class functions {
    public static int CAlsum( int a, int b){
        int sum  = a+b;
       return sum;
    }

    public static int multiply(int u, int v){
        int mul = u*v;
        return mul;
    }

    public static int factorial(int n){
        int f = 1;
        for(int i = 1; i<=n;i++){
            f = f*i;
        }
        return f;

    }
    public static int bincoef(int n , int r){
         int nfact = factorial(n);
         int rfact = factorial(r);
         int nmrfact = factorial(n-r);
         int mul = rfact*nmrfact;

         int bc = nfact/mul;
         return bc;

    }
    // public static boolean isprime(int n){
    //     boolean isp = true;
    //     for(int i = 2; i<=n-1;i++){
    //         if(n%i==0){
    //             isp = false;
    //             break;
    //         }
    //     }
    //     return isp;
    // }

    // optimized code
    public static boolean isprime( int n){
        if(n == 2){
            return true;
        }
        for(int i = 2; i<=Math.sqrt(n);i++){
            if(n%i == 0){
                return false;
            }

        }
        return true;
    }

    // prime in range
    public static void rangeprime(int n){
        for(int i = 2; i<=n;i++){
            if(isprime(i)){
                System.out.print(i+" ");
            }

        }
        System.out.println();

    }

    // binary to decimal
     public static void binToDec(int bNum){
        int Pow = 0;
        int decNum = 0;
        while(bNum>0){
            int lastDigit = bNum%10;
            decNum = decNum+(lastDigit*(int)Math.pow(2,Pow));
            Pow++;
            bNum = bNum/10;
        }
        System.out.println(decNum);
     }

    //  decimal to binary
    public static void dectobin(int d){
        int Pow =0;
        int bin = 0;
        while(d>0){
            int rem = d%2;
            bin = bin+rem*(int)Math.pow(10,Pow);
            Pow++;
            d = d/2;
        }
        System.out.println(bin);
    }
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
         dectobin(7);
           sc.close();


    }
}