Problem: There is a staircase with N steps. Takahashi is now standing at the foot of the stairs, that is, on the 0-th step. He can climb up one or two steps at a time.  However, the treads of the a_1-th, a_2-th, a_3-th, \ldots, a_M-th steps are broken, so it is dangerous to set foot on those steps.  How many are there to climb up to the top step, that is, the N-th step, without setting foot on the broken steps? Find the count modulo 1\ 000\ 000\ 007.

Submission attempts (in order):
def typical_stairs():
    n, m, dangerous = map(int, open(0).read().split())
    dangerous = set(dangerous)
    mod = 1000000007
    dp = [0] * (n + 1)
    dp[0] = 1
    if 1 not in dangerous:
        dp[1] = 1
    for i in range(2, n + 1):
        if i not in dangerous:
            dp[i] = (dp[i - 2] + dp[i - 1]) % mod
    print(dp[-1])


if __name__ == '__main__':
    typical_stairs()


def typical_stairs():
    n, m = map(int, input().split())
    dangerous = set(int(open(0).read().split()))
    mod = 1000000007
    dp = [0] * (n + 1)
    dp[0] = 1
    if 1 not in dangerous:
        dp[1] = 1
    for i in range(2, n + 1):
        if i not in dangerous:
            dp[i] = dp[i - 2] + dp[i - 1]
    print(dp[-1] % mod)


if __name__ == '__main__':
    typical_stairs()


def typical_stairs():
    n, m = map(int, input().split())
    dangerous = set(map(int, open(0).read().split()))
    mod = 1000000007
    dp = [0] * (n + 1)
    dp[0] = 1
    if 1 not in dangerous:
        dp[1] = 1
    for i in range(2, n + 1):
        if i not in dangerous:
            dp[i] = dp[i - 2] + dp[i - 1]
    print(dp[-1] % mod)


if __name__ == '__main__':
    typical_stairs()


def typical_stairs():
    n, m, *dangerous = map(int, open(0).read().split())
    dangerous = set(*dangerous)
    mod = 1000000007
    dp = [0] * (n + 1)
    dp[0] = 1
    if 1 not in dangerous:
        dp[1] = 1
    for i in range(2, n + 1):
        if i not in dangerous:
            dp[i] = (dp[i - 2] + dp[i - 1]) % mod
    print(dp[-1])


if __name__ == '__main__':
    typical_stairs()


import sys
input = sys.stdin.readline


def typical_stairs():
    n, m = map(int, input().split())
    dangerous = set(int(input()))
    mod = 1000000007
    dp = [0] * (n + 1)
    dp[0] = 1
    if 1 not in dangerous:
        dp[1] = 1
    for i in range(2, n + 1):
        if i not in dangerous:
            dp[i] = (dp[i - 2] + dp[i - 1]) % mod
    print(dp[-1])


if __name__ == '__main__':
    typical_stairs()


def typical_stairs():
    n, m = map(int, input().split())
    dangerous = set(open(0).read().split())
    mod = 1000000007
    dp = [0] * (n + 1)
    dp[0] = 1
    if 1 not in dangerous:
        dp[1] = 1
    for i in range(2, n + 1):
        if i not in dangerous:
            dp[i] = dp[i - 2] + dp[i - 1]
    print(dp[-1] % mod)


if __name__ == '__main__':
    typical_stairs()


import sys


def typical_stairs():
    n, m = map(int, input().split())
    dangerous = set(sys.stdin.readline())
    mod = 1000000007
    dp = [0] * (n + 1)
    dp[0] = 1
    if 1 not in dangerous:
        dp[1] = 1
    for i in range(2, n + 1):
        if i not in dangerous:
            dp[i] = dp[i - 2] + dp[i - 1]
    print(dp[-1] % mod)


if __name__ == '__main__':
    typical_stairs()


def typical_stairs():
    n, m, *dangerous = map(int, open(0).read().split())
    dangerous = set(dangerous)
    mod = 1000000007
    dp = [0] * (n + 1)
    dp[0] = 1
    if 1 not in dangerous:
        dp[1] = 1
    for i in range(2, n + 1):
        if i not in dangerous:
            dp[i] = (dp[i - 2] + dp[i - 1]) % mod
    print(dp[-1])


if __name__ == '__main__':
    typical_stairs()


Verdicts: Runtime Error

Runtime Error

Wrong Answer

Runtime Error

Runtime Error

Wrong Answer

Wrong Answer

Accepted