- 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
Check if a given array contains duplicate elements within k distance from each in C++
Here we will see how to check whether an unsorted array has duplicate elements within k distance from each other or not. Suppose a list of elements is {1, 2, 3, 1, 4, 5}, here if k = 3, then the program will return true, as the distance between two 1s is 3.
We will solve this using a hash table. The steps will be like below −
- Create one empty hash table
- For each index i, let the element e = arr[i] in the list, do
- if e is present in the hash table, then return true
- otherwise, add e to hash table, and remove (i-k)th element from the hash table if it exists, when i >= K.
Example
#include<iostream> #include<set> using namespace std; bool hasDuplicateWithDistK(int arr[], int n, int k) { set<int> element_set; for (int i = 0; i < n; i++) { if (element_set.find(arr[i]) != element_set.end()) return true; element_set.insert(arr[i]); if (i >= k) element_set.erase(arr[i-k]); } return false; } int main () { int arr[] = {10, 5, 3, 4, 3, 5, 6}; int n = sizeof(arr) / sizeof(arr[0]); if (hasDuplicateWithDistK(arr, n, 3)) cout << "Duplicate element has found"; else cout << "Duplicate element has not found"; }
Output
Duplicate element has found
Advertisements