Test results - Codility

Tasks Details

easy

1. PermMissingElem

Find the missing element in a given permutation.

100%

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)].

Solution

Programming language used Python

Time spent on task 1 minutes

Notes

not defined yet

Task timeline

Code: 11:19:28 UTC, py, final, score: 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

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

def solution(A):
    sumA = 0
    sumFull = 0
    
    for i in A:
        sumA += i
    
    for i in range(1, len(A) + 2):
        sumFull += i
    
    return sumFull - sumA
    pass

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N)

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example
example test

✔

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empty_and_single
empty list and single element

✔

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missing_first_or_last
the first or the last element is missing

✔

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single
single element

✔

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double
two elements

✔

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simple
simple test

✔

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medium1
medium test, length = ~10,000

✔

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medium2
medium test, length = ~10,000

✔

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large_range
range sequence, length = ~100,000

✔

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large1
large test, length = ~100,000

✔

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large2
large test, length = ~100,000

✔