Extended Euclid’s Algorithm code example

Example 1: extended euclidean python

def extendEuclidean(a, b, s1=1, s2=0, t1=0, t2=1):
    
    if b:
        r=a%b
        return extendEuclidean(b, r, s2, s1-s2*(a//b), t2, t1-t2*(a//b))
    
    return a, s1, t1

Example 2: implementing euclid's extended algorithm

import java.util.Scanner;
class Lab3{
     //euclids algorithm
     int euclid(int a, int b){
          if(b==0)
               return a;
          else
               return euclid(b, a%b);
          }
     //euclids extended algorithm
     int exeuclid(int a, int m)
     {
          int A3 = m;
          int A2 = 0, A1 = 1;
          if (m == 1)
               return 0;

          while (a > 1)
          {
               // q is quotient
               int q = a / m;

               int t = m;

               // m is remainder now, process
               // same as Euclid's algo
               m = a % m;
               a = t;
               t = A2;

               // Update A1 and A2
               A2 = A1 - q * A2;
               A1 = t;
          }

          // Make A1 positive
          if (A1 < 0)
          A1 += A3;
          return A1;
     }
     public static void main(String[] args) {
          Lab3 ob = new Lab3();
          int x, y, choice;

          Scanner input = new Scanner(System.in);
          System.out.println("Enter Choice \n Enter 1 for gcd and 2 for extended ed");
          choice=input.nextInt();
          switch(choice)
          {
               case 1:
                    int output;
                    System.out.println("Enter the first number");
                    x = input.nextInt();
                    System.out.println("Enter the second number");
                    y = input.nextInt();
                    output = ob.euclid(x, y);
                    System.out.println("GCD is:"+output);
                    break;
               case 2:
                    System.out.println("To Find Inverse");
                    int m, b;
                    System.out.println("Enter m");
                    m=input.nextInt();
                    System.out.println("Enter b");
                    b = input.nextInt();
                    System.out.println("Inverse is equal to: "+ob.exeuclid(m, b));
                    break;
               default:
                    System.out.println("Wrong Choice");
          }

     }
}Code language: JavaScript (javascript)

Example 3: implementing euclid's extended algorithm

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int exeuclid(int a, int m)
{
     int A3 = m;
     int A2 = 0, A1 = 1;

     if (m == 1)
          return 0;

     while (a > 1)
     {
          // q is quotient
          int q = a / m;

          int t = m;

          // m is remainder now, process
          // same as Euclid's algo
          m = a % m;
          a = t;
          t = A2;

          // Update A1 and A2
          A2 = A1 - q * A2;
          A1 = t;
      }

     // Make A1 positive
     if (A1 < 0)
     A1 += A3;
     return A1;
}Code language: JavaScript (javascript)