Python: Find the missing number in a given array of numbers between 10 and 20

Last update on May 28 2022 13:31:31 (UTC/GMT +8 hours)

Python: Array Exercise-24 with Solution

Write a Python program to find the missing number in a given array of numbers between 10 and 20.

Sample Solution-1:

Python Code:

import array as arr
def test(nums):
    return sum(range(10, 21)) - sum(list(nums))

array_num = arr.array('i', [10, 11, 12, 13, 14, 16, 17, 18, 19, 20])
print("Original array:")
for i in range(len(array_num)):    
    print(array_num[i], end=' ')
print("\nMissing number in the said array (10-20): ",test(array_num))
 
array_num = arr.array('i', [10, 11, 12, 13, 14, 15, 16, 17, 18, 19])
print("\nOriginal array:")
for i in range(len(array_num)):    
    print(array_num[i], end=' ')
print("\nMissing number in the said array (10-20): ",test(array_num))

Sample Output:

Original array:
10 11 12 13 14 16 17 18 19 20 
Missing number in the said array (10-20):  15

Original array:
10 11 12 13 14 15 16 17 18 19 
Missing number in the said array (10-20):  20

Flowchart:

Sample Solution-2:

Python Code:

import array as arr
def test(nums):
    return 165 - sum(list(nums))

array_num = arr.array('i', [10, 11, 12, 13, 14, 16, 17, 18, 19, 20])
print("Original array:")
for i in range(len(array_num)):    
    print(array_num[i], end=' ')
print("\nMissing number in the said array (10-20): ",test(array_num))
 
array_num = arr.array('i', [10, 11, 12, 13, 14, 15, 16, 17, 18, 19])
print("\nOriginal array:")
for i in range(len(array_num)):    
    print(array_num[i], end=' ')
print("\nMissing number in the said array (10-20): ",test(array_num))

Sample Output:

Original array:
10 11 12 13 14 16 17 18 19 20 
Missing number in the said array (10-20):  15

Original array:
10 11 12 13 14 15 16 17 18 19 
Missing number in the said array (10-20):  20

Flowchart:

Python Code Editor:

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Python: Tips of the Day

Find current directory and file's directory:

To get the full path to the directory a Python file is contained in, write this in that file:

import os dir_path = os.path.dirname(os.path.realpath(__file__))

(Note that the incantation above won't work if you've already used os.chdir() to change your current working directory, since the value of the __file__ constant is relative to the current working directory and is not changed by an os.chdir() call.)

To get the current working directory use

import os cwd = os.getcwd()

Documentation references for the modules, constants and functions used above:

The os and os.path modules.

The __file__ constant

os.path.realpath(path) (returns "the canonical path of the specified filename, eliminating any symbolic links encountered in the path")

os.path.dirname(path) (returns "the directory name of pathname path")

os.getcwd() (returns "a string representing the current working directory")

os.chdir(path) ("change the current working directory to path")

Ref: https://bit.ly/3fy0R6m