[Python] 4.1. FrogRiverOne

https://app.codility.com/programmers/lessons/4-counting_elements/

4. Counting Elements lesson - Learn to Code - Codility

---

정답률: 100%
시간복잡도: O(N)

def solution(X, A):

​​​​check = [1] + [0] * X
​​​​cnt = 0
​​​​for K in range(len(A)):
​​​​​​​​if check[A[K]] == 0:
​​​​​​​​​​​​check[A[K]] = 1
​​​​​​​​​​​​cnt += 1
​​​​​​​​if cnt == X:
​​​​​​​​​​​​return K

​​​​if cnt != X:
​​​​​​​​return -1