Coding Round in Interview for Data Scientist Role at a Bank (17 Nov 2023)

Task 1

Write a function:

    def solution(A)

that, given an array A of N integers, returns the smallest positive integer (greater than 0) that does not occur in A.

For example, given A = [1, 3, 6, 4, 1, 2], the function should return 5.

Given A = [1, 2, 3], the function should return 4.

Given A = [−1, −3], the function should return 1.

Write an efficient algorithm for the following assumptions:

        N is an integer within the range [1..100,000];
        each element of array A is an integer within the range [−1,000,000..1,000,000].

A brute-force solution to this problem that will fail the performance tests will look like this:


def solution(A):
    # a_sort = sorted(A)
    rtn = -1
    for i in range(1, 100001):
        if i in A: # This is the most time consuming instruction of this code that runs repeatedly for all of i(s)
            continue
        else:
            rtn = i
            break
    return rtn 


Task 2




Task 3

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