Cobility Lesson3 - PermMissingElem

Cobility Lesson3 - PermMissingElem

https://app.codility.com/demo/results/training4QR7VV-HFX/

Test results - Codility

 

문제

An array A consisting of N different integers is given. The array contains integers in the range [1..(N + 1)], which means that exactly one element is missing.

Your goal is to find that missing element.

Write a function:

def solution(A)

that, given an array A, returns the value of the missing element.

For example, given array A such that:

A[0] = 2 A[1] = 3 A[2] = 1 A[3] = 5

the function should return 4, as it is the missing element.

Write an efficient algorithm for the following assumptions:

• N is an integer within the range [0..100,000];
• the elements of A are all distinct;
• each element of array A is an integer within the range [1..(N + 1)].

 

정답

def solution(A):

    big=max(A)

    s=sum(A)
    s_key=0
    for i in range(1,big+1):
        s_key+=i
   
    return s_key-s

 

결과

 

- > 누락 숫자가 맨 마지막일 확률을 생각 못 함, 빈 배열이 들어갈 확률을 생각 못 함

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정답-Retry

def solution(A):
  
    if len(A)>=1:
        big=max(A)

        s=sum(A)
        s_key=0
        for i in range(1,big+1):
            s_key+=i
        if s_key==s:
            result= big+1
        else:
            result = s_key-s
    else:
        result=1

    return result

 

결과-Retry