#100DayOfCode - Day 43/100 - GCD algo stress test

GCDAlgoStressTest.go

package main

import (
	"fmt"
	"math/rand"
)

func main() {
	var gChan chan int = make(chan int)
	var geChan chan int = make(chan int)
	for {
		a := rand.Intn(100000)
		b := rand.Intn(100000)
		fmt.Printf("Val a,b: %v, %v\t", a, b)
		go func() {
			g := gcd(a, b)
			fmt.Printf("GCD: %v\t", g)
			gChan <- g
		}()
		go func() {
			ge := gcdEfficient(a, b)
			fmt.Printf("GCD-E: %v\t", ge)
			geChan <- ge
		}()
		if <-gChan != <-geChan {
			fmt.Printf("Result: False\n")
			break
		}
		fmt.Printf("Result: True\n")
	}
}

// slow algorithm for very large number such as 63473574
func gcd(a, b int) int {
	if a == 0 {
		return b
	}
	if b == 0 {
		return a
	}
	r := 1
	var smaller int
	if a < b {
		smaller = a
	} else {
		smaller = b
	}
	for i := 1; i <= smaller; i++ {
		if a%i == 0 && b%i == 0 {
			r = i
		}
	}
	return r
}

// Euclidean algorithm
func gcdEfficient(a, b int) int {
	if b == 0 {
		return a
	}
	at := a % b
	return gcdEfficient(b, at)
}