# Sum of elements in an array with frequencies greater than or equal to that element

Given an array arr[] of N integers. The task is to find the sum of the elements which have frequencies greater than or equal to that element in the array.

Examples:

```Input: arr[] = {2, 1, 1, 2, 1, 6}
Output: 3
The elements in the array are {2, 1, 6}
Where,
2 appear 2 times which is greater than equal to 2 itself.
1 appear 3 times which is greater than 1 itself.
But 6 appears 1 time which is not greater than or equals to 6.
So, sum = 2 + 1 = 3.

Input: arr[] = {1, 2, 3, 3, 2, 3, 2, 3, 3}
Output: 6
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach:

• Traverse the array and store the frequencies of all the elements in an unordered_map in C++ or equivalent data structure in any other programming language.
• Calculate the sum of elements having frequencies greater than or equal to that element.

Below is the implementation of the above approach:

## C++

 `// C++ program to find sum of elements ` `// in an array having frequency greater ` `// than or equal to that element ` ` `  `#include ` `using` `namespace` `std; ` ` `  `// Function to return the sum of elements ` `// in an array having frequency greater ` `// than or equal to that element ` `int` `sumOfElements(``int` `arr[], ``int` `n) ` `{ ` `    ``bool` `prime[n + 1]; ` `    ``int` `i, j; ` ` `  `    ``// Map is used to store ` `    ``// element frequencies ` `    ``unordered_map<``int``, ``int``> m; ` `    ``for` `(i = 0; i < n; i++) ` `        ``m[arr[i]]++; ` ` `  `    ``int` `sum = 0; ` ` `  `    ``// Traverse the map using iterators ` `    ``for` `(``auto` `it = m.begin(); it != m.end(); it++) { ` ` `  `        ``// Calculate the sum of elements ` `        ``// having frequencies greater than ` `        ``// or equal to the element itself ` `        ``if` `((it->second) >= (it->first)) { ` `            ``sum += (it->first); ` `        ``} ` `    ``} ` ` `  `    ``return` `sum; ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` `    ``int` `arr[] = { 1, 2, 3, 3, 2, 3, 2, 3, 3 }; ` `    ``int` `n = ``sizeof``(arr) / ``sizeof``(arr); ` ` `  `    ``cout << sumOfElements(arr, n); ` ` `  `    ``return` `0; ` `} `

## Java

 `// Java program to find sum of elements ` `// in an array having frequency greater ` `// than or equal to that element ` `import` `java.util.*; ` `class` `Solution ` `{ ` ` `  `// Function to return the sum of elements ` `// in an array having frequency greater ` `// than or equal to that element ` `static` `int` `sumOfElements(``int` `arr[], ``int` `n) ` `{ ` `    ``boolean` `prime[] = ``new` `boolean``[n + ``1``]; ` `    ``int` `i, j; ` ` `  `    ``// Map is used to store ` `    ``// element frequencies ` `    ``HashMap m= ``new` `HashMap(); ` `    ``for` `(i = ``0``; i < n; i++) ` `        ``{ ` `            ``if``(m.get(arr[i])==``null``) ` `            ``m.put(arr[i],``1``); ` `            ``else` `            ``m.put(arr[i],m.get(arr[i])+``1``); ` `        ``} ` ` `  `    ``int` `sum = ``0``; ` `        ``// Getting an iterator  ` `        ``Iterator hmIterator = m.entrySet().iterator();  ` `   `  `   `  `    ``// Traverse the map using iterators ` `        ``while` `(hmIterator.hasNext()) {  ` `            ``Map.Entry mapElement = (Map.Entry)hmIterator.next(); ` ` `  `        ``// Calculate the sum of elements ` `        ``// having frequencies greater than ` `        ``// or equal to the element itself ` `        ``if` `(((``int``)mapElement.getValue()) >= ((``int``)mapElement.getKey())) { ` `            ``sum += ((``int``)mapElement.getKey()); ` `        ``} ` `    ``} ` ` `  `    ``return` `sum; ` `} ` ` `  `// Driver code ` `public` `static` `void` `main(String args[]) ` `{ ` `    ``int` `arr[] = { ``1``, ``2``, ``3``, ``3``, ``2``, ``3``, ``2``, ``3``, ``3` `}; ` `    ``int` `n = arr.length; ` ` `  `    ``System.out.println(sumOfElements(arr, n)); ` ` `  ` ``} ` `} ` `//contributed by Arnab Kundu `

## Python3

 `# Python3 program to find sum of elements  ` `# in an array having frequency greater  ` `# than or equal to that element ` ` `  `# Function to return the sum of elements  ` `# in an array having frequency greater  ` `# than or equal to that element  ` `def` `sumOfElements(arr, n) : ` ` `  `    ``# dictionary is used to store  ` `    ``# element frequencies  ` `    ``m ``=` `dict``.fromkeys(arr, ``0``) ` ` `  `    ``for` `i ``in` `range``(n) : ` `            ``m[arr[i]] ``+``=` `1` ` `  `    ``sum` `=` `0` ` `  `    ``# traverse the dictionary ` `    ``for` `key,value ``in` `m.items() : ` ` `  `        ``# Calculate the sum of elements  ` `        ``# having frequencies greater than  ` `        ``# or equal to the element itself  ` `        ``if` `value >``=` `key : ` `                ``sum` `+``=` `key ` ` `  `    ``return` `sum` ` `  `# Driver code ` `if` `__name__ ``=``=` `"__main__"` `: ` ` `  `    ``arr ``=` `[``1``, ``2``, ``3``, ``3``, ``2``, ``3``, ``2``, ``3``, ``3``] ` `    ``n ``=` `len``(arr) ` ` `  `    ``print``(sumOfElements(arr, n)) ` ` `  `# This code is contributed by Ryuga `

## C#

 `// C# program to find sum of elements ` `// in an array having frequency greater ` `// than or equal to that element ` `using` `System; ` `using` `System.Collections.Generic; ` ` `  `class` `GFG ` `{ ` ` `  `    ``// Function to return the sum of elements ` `    ``// in an array having frequency greater ` `    ``// than or equal to that element ` `    ``static` `int` `sumOfElements(``int` `[]arr, ``int` `n) ` `    ``{ ` `        ``bool` `[]prime = ``new` `bool``[n + 1]; ` `        ``int` `i; ` `     `  `        ``// Map is used to store ` `        ``// element frequencies ` `        ``Dictionary<``int``, ``int``> m= ``new` `Dictionary<``int``,``int``>(); ` `        ``for` `(i = 0; i < n; i++) ` `            ``{ ` `                ``if``(!m.ContainsKey(arr[i])) ` `                    ``m.Add(arr[i],1); ` `                ``else` `                ``{ ` `                    ``var` `val = m[arr[i]]; ` `                    ``m.Remove(arr[i]); ` `                    ``m.Add(arr[i], val + 1); ` `                ``} ` `             `  `            ``} ` `     `  `            ``int` `sum = 0; ` `            ``// Calculate the sum of elements ` `            ``// having frequencies greater than ` `            ``// or equal to the element itself ` `            ``foreach``(KeyValuePair<``int``, ``int``> entry ``in` `m) ` `            ``{ ` `                ``if``(entry.Value >= entry.Key) ` `                ``{ ` `                    ``sum+=entry.Key; ` `                ``} ` `            ``} ` `     `  `        ``return` `sum; ` `    ``} ` `     `  `    ``// Driver code ` `    ``public` `static` `void` `Main(String []args) ` `    ``{ ` `        ``int` `[]arr = { 1, 2, 3, 3, 2, 3, 2, 3, 3 }; ` `        ``int` `n = arr.Length; ` `     `  `        ``Console.WriteLine(sumOfElements(arr, n)); ` `    ``} ` `} ` ` `  `// This code has been contributed by 29AjayKumar `

Output:

```6
```

Time complexity : O(n)

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.

My Personal Notes arrow_drop_up Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.

Article Tags :
Practice Tags :

1

Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.