Program to find kth missing positive number in an array in Python

Suppose we have an array called nums with positive sorted strictly increasing values, and also have an integer k. We have to find the kth positive integer that is missing from this array.

So, if the input is like nums = [1,2,4,8,12], k = 6, then the output will be 10 because the missing numbers are [3,5,6,7,9,10,11], here the 6th term is 10.

To solve this, we will follow these steps −

• nums := a new set from the elements present in nums

• count := 0

• num := 1

• while count < k, do

  • if num is not in nums, then

    • count := count + 1

  • if count is same as k, then

    • return num

  • num := num + 1

• return num

Example (Python)

Let us see the following implementation to get better understanding −

 Live Demo

def solve(nums, k):
   nums = set(nums)
   count = 0
   num = 1
   while count < k:
      if num not in nums:
         count += 1
      if count == k:
         return num
      num += 1
   return num

nums = [1,2,4,8,12]
k = 6
print(solve(nums, k))

Input

[1,2,4,8,12], 6

Output

10

Arnab Chakraborty

Published on 17-May-2021 12:27:08

• Related Questions & Answers
• Program to find the kth missing number from a list of elements in Python
• Program to find first positive missing integer in range in Python
• First Missing Positive in Python
• Write a program in C++ to find the missing positive number in a given array of unsorted integers
• Write a program in Java to find the missing positive number in a given array of unsorted integers
• PHP program to find missing elements from an array
• Kth odd number in an array in C++
• Kth Largest Element in an Array in Python
• Missing Number in Python
• Program to find lowest possible integer that is missing in the array in Python
• Kth Largest Element in an Array
• Find four missing numbers in an array containing elements from 1 to N in Python
• Java program to find the largest number in an array
• Java program to find the smallest number in an array
• Python Program to find largest element in an array