1. Two positive integers i and j are considered to be co-prime if there exists no integer greater than 1 that divides them both. Write a function co-prime that has two input parameters, i and j, and returns a value of 1 for true if i and j are co-prime. Otherwise, co-prime should return a value of 0 for false. Also, write a driver program to test the your function. You should specify the input / output format of your program.
使用欧几里得算法(辗转相除法)
Hint - You can use the Euclidean Algorithm which is outlined as below:
To find the greatest common divisor between two natural numbers, divide one by the other and take the remainder (i.e. modulus operation). If the remainder is non-zero, take the divider and the modulus as the input and repeat the modulus operation until the modulus becomes zero. The last divider used before the modulus becomes zero is the greatest common divisor (GCD) between the two numbers that we start out with. If the GCD is 1, then the two numbers are co-prime (i.e. relatively prime). (30 points)
Example 1: Find the GCD of 84 and 140.
140 % 84 = 56 , 84 % 56 = 28, 56 % 28 = 0
\ the GCD of 84 and 140 is 28 Þ not co-prime.
Example 2: Find the GCD of 12 and 35
12 % 35 = 12, 35 % 12 = 11, 12 % 11 = 1, 11 % 1 = 0
\ the GCD of 35 and 12 is 1 Þ co-prime.