方法集锦5_组合_Python

1.求所有的长度为K的组合(不重复)

例:[1,2,3,4,5]

所有组合:[[1, 2, 3], [1, 2, 4], [1, 2, 5], [1, 3, 4], [1, 3, 5], [1, 4, 5], [2, 3, 4], [2, 3, 5], [2, 4, 5], [3, 4, 5]]

a = [1,2,3,4,5]

def search(results, arr, k, path):
    if (k == 0):
        results.append(path)
        return
    
    for i in range(len(arr)):
        search(results, arr[i + 1: ], k - 1, path + [arr[i]])

    return results 

result = search([], a, 3, [])
print(result)

2.判断是否素数

def isPrime(num):
    for i in range(2, num):
        if num%i == 0:
            return False
    return True 

result = isPrime(7)
print(result)