https://codility.com/demo/results/training6RCQWX-6ZG/

PermCheck.py

# you can write to stdout for debugging purposes, e.g.
# print "this is a debug message"

def solution(A):
    
    N = len(A)
    
    if not N: return 0
        
    count = N
    result = 1
    
    A_ = [0] * N
    
    for i in A:
        if i > N:
            result = 0
            break
        elif i <= N and not A_[i-1]:
            A_[i-1] = 1
            count -= 1
    
    if count:
        result = 0
    
    return result