# Count elements such that there are exactly X elements with values greater than or equal to X

Given an array *arr* of *N* integers, the task is to find the number of elements that satisfy the following condition:

If the element is *X* then there has to be exactly *X* number of elements in the array (excluding the number *X*) which are greater than or equal to *X*

**Examples:**

Input:arr[] = {1, 2, 3, 4}Output:1 Only element 2 satisfies the condition as there are exactly 2 elements which are greater than or equal to 2 (3, 4) except 2 itself.Input:arr[] = {5, 5, 5, 5, 5}Output:0

**Approach:** The problem involves efficient searching for each arr[i] element the number of arr[j]’s (i != j) which are greater than or equal to arr[i].

- Sort the array in ascending order.
- For every element arr[i], using binary search get the count of all the elements that are greater than or equal to arr[i] except arr[i] itself.
- If the count is equal to arr[i] then increment the result.
- Print the value of the result in the end.

Below is the implementation of the above approach:

## C++

`// C++ implementation of the approach ` `#include <bits/stdc++.h> ` `using` `namespace` `std; ` `#define ll long long ` ` ` `ll ` `int` `getCount(vector<ll ` `int` `> v, ` `int` `n) ` `{ ` ` ` `// Sorting the vector ` ` ` `sort((v).begin(), (v).end()); ` ` ` `ll ` `int` `cnt = 0; ` ` ` `for` `(ll ` `int` `i = 0; i < n; i++) { ` ` ` ` ` `// Count of numbers which ` ` ` `// are greater than v[i] ` ` ` `ll ` `int` `tmp = v.end() - 1 ` ` ` `- upper_bound((v).begin(), (v).end(), v[i] - 1); ` ` ` ` ` `if` `(tmp == v[i]) ` ` ` `cnt++; ` ` ` `} ` ` ` `return` `cnt; ` `} ` ` ` `// Driver code ` `int` `main() ` `{ ` ` ` `ll ` `int` `n; ` ` ` `n = 4; ` ` ` `vector<ll ` `int` `> v; ` ` ` `v.push_back(1); ` ` ` `v.push_back(2); ` ` ` `v.push_back(3); ` ` ` `v.push_back(4); ` ` ` ` ` `cout << getCount(v, n); ` ` ` `return` `0; ` `} ` |

*chevron_right*

*filter_none*

## Java

`// Java implementation of the approach ` `import` `java.util.*; ` ` ` `class` `GFG ` `{ ` ` ` `static` `int` `getCount(` `int` `[] v, ` `int` `n) ` ` ` `{ ` ` ` ` ` `// Sorting the vector ` ` ` `Arrays.sort(v); ` ` ` `int` `cnt = ` `0` `; ` ` ` `for` `(` `int` `i = ` `0` `; i < n; i++) ` ` ` `{ ` ` ` ` ` `// Count of numbers which ` ` ` `// are greater than v[i] ` ` ` `int` `tmp = n - ` `1` `- upperBound(v, n, v[i] - ` `1` `); ` ` ` `if` `(tmp == v[i]) ` ` ` `cnt++; ` ` ` `} ` ` ` `return` `cnt; ` ` ` `} ` ` ` ` ` `// Function to implement upper_bound() ` ` ` `static` `int` `upperBound(` `int` `[] array, ` ` ` `int` `length, ` `int` `value) ` ` ` `{ ` ` ` `int` `low = ` `0` `; ` ` ` `int` `high = length; ` ` ` `while` `(low < high) ` ` ` `{ ` ` ` `final` `int` `mid = (low + high) / ` `2` `; ` ` ` `if` `(value >= array[mid]) ` ` ` `{ ` ` ` `low = mid + ` `1` `; ` ` ` `} ` ` ` `else` ` ` `{ ` ` ` `high = mid; ` ` ` `} ` ` ` `} ` ` ` `return` `low; ` ` ` `} ` ` ` ` ` `// Driver Code ` ` ` `public` `static` `void` `main(String[] args) ` ` ` `{ ` ` ` `int` `n = ` `4` `; ` ` ` `int` `[] v = { ` `1` `, ` `2` `, ` `3` `, ` `4` `}; ` ` ` `System.out.println(getCount(v, n)); ` ` ` `} ` `} ` ` ` `// This code is contributed by ` `// sanjeev2552 ` |

*chevron_right*

*filter_none*

## Python3

`# Python3 implementation of the approach ` `from` `bisect ` `import` `bisect as upper_bound ` ` ` `def` `getCount(v, n): ` ` ` ` ` `# Sorting the vector ` ` ` `v ` `=` `sorted` `(v) ` ` ` `cnt ` `=` `0` ` ` `for` `i ` `in` `range` `(n): ` ` ` ` ` `# Count of numbers which ` ` ` `# are greater than v[i] ` ` ` `tmp ` `=` `n ` `-` `1` `-` `upper_bound(v, v[i] ` `-` `1` `) ` ` ` ` ` `if` `(tmp ` `=` `=` `v[i]): ` ` ` `cnt ` `+` `=` `1` ` ` `return` `cnt ` ` ` `# Driver codemain() ` `n ` `=` `4` `v ` `=` `[] ` `v.append(` `1` `) ` `v.append(` `2` `) ` `v.append(` `3` `) ` `v.append(` `4` `) ` ` ` `print` `(getCount(v, n)) ` ` ` `# This code is contributed by Mohit Kumar ` |

*chevron_right*

*filter_none*

## C#

`// C# implementation of the approach ` `using` `System; ` ` ` `class` `GFG ` `{ ` ` ` `static` `int` `getCount(` `int` `[] v, ` `int` `n) ` ` ` `{ ` ` ` ` ` `// Sorting the vector ` ` ` `Array.Sort(v); ` ` ` `int` `cnt = 0; ` ` ` `for` `(` `int` `i = 0; i < n; i++) ` ` ` `{ ` ` ` ` ` `// Count of numbers which ` ` ` `// are greater than v[i] ` ` ` `int` `tmp = n - 1 - upperBound(v, n, v[i] - 1); ` ` ` `if` `(tmp == v[i]) ` ` ` `cnt++; ` ` ` `} ` ` ` `return` `cnt; ` ` ` `} ` ` ` ` ` `// Function to implement upper_bound() ` ` ` `static` `int` `upperBound(` `int` `[] array, ` ` ` `int` `length, ` `int` `value) ` ` ` `{ ` ` ` `int` `low = 0; ` ` ` `int` `high = length; ` ` ` `while` `(low < high) ` ` ` `{ ` ` ` `int` `mid = (low + high) / 2; ` ` ` `if` `(value >= array[mid]) ` ` ` `{ ` ` ` `low = mid + 1; ` ` ` `} ` ` ` `else` ` ` `{ ` ` ` `high = mid; ` ` ` `} ` ` ` `} ` ` ` `return` `low; ` ` ` `} ` ` ` ` ` `// Driver Code ` ` ` `public` `static` `void` `Main(String[] args) ` ` ` `{ ` ` ` `int` `n = 4; ` ` ` `int` `[] v = { 1, 2, 3, 4 }; ` ` ` `Console.WriteLine(getCount(v, n)); ` ` ` `} ` `} ` ` ` `// This code is contributed by PrinciRaj1992 ` |

*chevron_right*

*filter_none*

**Output:**

1

Don’t stop now and take your learning to the next level. Learn all the important concepts of Data Structures and Algorithms with the help of the most trusted course: **DSA Self Paced**. Become industry ready at a student-friendly price.

## Recommended Posts:

- Noble integers in an array (count of greater elements is equal to value)
- Count of elements whose absolute difference with the sum of all the other elements is greater than k
- Count of Array elements to be divided by 2 to make at least K elements equal
- Replace repeating elements with greater that greatest values
- Count smaller elements on right side and greater elements on left side using Binary Index Tree
- Count of elements which are equal to the XOR of the next two elements
- Length of Smallest Subsequence such that sum of elements is greater than equal to K
- Sum of elements in an array with frequencies greater than or equal to that element
- Adding elements of an array until every element becomes greater than or equal to k
- Length of longest subarray in which elements greater than K are more than elements not greater than K
- Count subarrays with all elements greater than K
- Count elements whose sum with K is greater than max element
- Count positions such that all elements before it are greater
- Count of greater elements for each element in the Array
- Count the subarray with sum strictly greater than the sum of remaining elements
- Count the number of elements which are greater than any of element on right side of an array
- Reduce the array by deleting elements which are greater than all elements to its left
- Count sub-arrays which have elements less than or equal to X
- Merge first two minimum elements of the array until all the elements are greater than K
- Minimum elements to be removed to make count of 0s and 1s equal

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.