Sherlock and GCD

 1 import fractions, functools, sys
 2
 3
 4 if __name__ == ‘__main__‘:
 5     T = int(sys.stdin.readline())
 6
 7     for _ in range(T):
 8         N = int(sys.stdin.readline())
 9         A = list(map(int, sys.stdin.readline().split()))
10
11         gcd = functools.reduce(fractions.gcd, A) # reduce函数的理解
12         print(‘YES‘ if gcd == 1 else ‘NO‘)

Link:　　https://www.hackerrank.com/challenges/sherlock-and-gcd

学习：　　深度抽象问题　　　　不断地抽象问题的本质，层级越高，越简单！　　reduce　　　　循环apply fuc　　gcd　　　　greatest commen diviosr