missing_num_sum.py

from typing import List

tests = {
    1: [3,0,1],
    2: [0, 1],
    3: [9,6,4,2,3,5,7,0,1],
    4: [0],
    5: [1]
}
res = {
    1: 2,
    2: 2,
    3: 8,
    4: 1,
    5: 0
}

def missingNumber(nums: List[int]) -> int:
    expected_sum = 0
    nums_sum = 0

    for i in range(len(nums) + 1):
       expected_sum += i

    for _, num in enumerate(nums):
       nums_sum += num

    return expected_sum - nums_sum

def check_result(index: int, output: int):
    if index > len(tests):
        raise RuntimeError(f'Failed to get {index}th case')
    return output == res.get(index, -1)

def main():
    for index, input_list in tests.items():
        num = missingNumber(input_list)

        if check_result(index, num):
            print(f'Test case {index} is correct: value {num}')
        else:
            print(f'Test case {index} is failed: value {num}')

if __name__ == '__main__':
    main()