Question

Write a function that takes a list of integer number and returns the greatest common divisor of all numbers in the list.

WRITE THE CODE IN PYTHON

Answer 1

Python code to calculate GCD of a list of integers is given below (gcd_list). gcd_list uses for loop to iterate through the list and in turn calls gcd function (defined at the top) to get GCD of two numbers at a time. You can pass your list of integers to gcd_list and it'll return the GCD value for the complete list.

#gcd function to calculate GCD of two numbers
def gcd (a,b):
    if (b == 0):
        return a
    else:
        return gcd (b, a % b)

#gcd_list function to calculate GCD for list of numbers using for loop and gcd function
def gcd_list (listOfNums):
    gcdVal = listOfNums[0]
    for c in listOfNums[1::]:
        gcdVal = gcd (gcdVal , c)
    return gcdVal

#Sample Runs

#Define list of integers
intList1 = [6, 12, 30, 36, 60, 90, 99]
#Print final GCD value by calling gcd_list with intList as argument
print (gcd_list(intList1))
#Define list of integers
intList2 = [2, 4, 6, 8, 10]
#Print final GCD value by calling gcd_list with intList as argument
print (gcd_list(intList2))
intList3 = [10, 15, 5, 25, 20]
#Print final GCD value by calling gcd_list with intList as argument
print (gcd_list(intList3))

OUTPUT:

3                                                                                                                                                                                 

2                                                                                                                                                                                 

5