PAT-1152 Google Recruitment 解答(with python)

1.Description：

Now you are asked to solve a more general problem: find the first K-digit prime in consecutive digits of any given L-digit number.

 

2.Example：

Input:
20 5
23654987725541023819
Output:
49877

Input:
10 3
2468024680
Output:
404

3.solutions:

"""
    created by sheepcore on 2020-03-01
"""


def isPrime(x):
    if x < 2:
        return False
    for n in range(2, int(x ** 0.5 + 1)):
        if x % n == 0:
            return False
            break
    else:
        return True


def removeHeadZeros(x):
    idx = 0
    while x[idx] == '0':
        idx += 1
    return eval(x[idx:]), idx


if __name__ == "__main__":
    length, bits = input().split()
    num = input()
    i = 0
    while i <= eval(length) - eval(bits):
        x, zeros = removeHeadZeros(num[i:i+eval(bits)])
        if isPrime(x) is True:
            if zeros == 0:
                print(x, end="")
            else:
                print("0"*zeros + str(x), end="")
            break
        i += 1
    if i > eval(length) - eval(bits):
        print("404", end="")