Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
k-th missing element in an unsorted array in C++
In this tutorial, we are going to write a program that finds out the k-th missing element in the given unsorted array.
Find the k-th number that is missing from min to max in the given unsorted array. Let's see the steps to solve the problem.
- Initialise the unsorted array.
- Insert all the elements into a set.
- Find the max and min elements from the array.
- Write a loop that iterates from min to max and maintain a variable for the count.
- If the current element is present in the set, then increment the count.
- If the count is equal to k, then return i.
Example
Let's see the code.
#include <bits/stdc++.h>
using namespace std;
int findMissingNumber(int arr[], int n, int k) {
unordered_set<int> numbers;
int count = 0;
for (int i = 0; i < n; i++) {
numbers.insert(arr[i]);
}
int max = *max_element(arr, arr + n);
int min = *min_element(arr, arr + n);
for (int i = min + 1; i < max; i++) {
if (numbers.find(i) == numbers.end()) {
count++;
}
if (count == k) {
return i;
}
}
return -1;
}
int main() {
int arr[] = { 1, 10, 3, 2, 5 }, n = 5;
int k = 3;
cout << findMissingNumber(arr, n, k) << endl;
return 0;
}Output
If you run the above code, then you will get the following result.
7
Conclusion
If you have any queries in the tutorial, mention them in the comment section.
Updated on: 09-Apr-2021
117 Views
Advertisements