两种不同方法求最大公约数GCD（Greatest Common Divisor）（Python）

方法一：从1开始依次查找

# pseudocode
gcd = 1
int k = 2 #Possible gcd
while k <= n1 and k <= n2:
	if n1 % k == 0 and n2 % k == 0:
		gcd = k
	k += 1 

Python3实现

#Finding the Greatest Common Divisor

n1 = eval(input("Enter first number: "))
n2 = eval(input("Enter second number: "))

gcd = 1
k = 2
while k <= n1 and k <= n2:
    if n1 % k == 0 and n2 % k == 0:
        gcd = k
    k += 1

print("The greatest common divisor for", n1, "and ", n2, "is", gcd)
input("press Enter: ")

方法二：欧几里得算法（辗转相除法）

原理解释如连接：英文算法解释

通俗易懂算法解释

Python3代码实现

#Finding the Greatest Common Divisor Euclid's Algorithm

n1 = eval(input("Enter first number: "))
n2 = eval(input("Enter second number: "))

number1, number2 = n1, n2
if n1 < n2:
    n1, n2 = n2, n1

gcd = 1
while n2 != 0:
    gcd = n1 % n2
    n1 = n2
    n2 = gcd
    print("gcd: n1: n2 :", gcd, n1, n2)
gcd = n1

print("The greatest common divisor for", number1, "and ", number2, "is", gcd)
input("press Enter: ")