# Count All Occurrences of an Element in an Array

Count All Occurrences of an Element in an Array” is a basic problem of array data structure. Here, we are given an array of size ‘n’ and an element ‘x’. Our task is to write a program to count all occurrences of an element in an array.

Example (Count All Occurrences of an Element in an Array):

```INPUT:
Enter the size of an array: 10
Enter Array Elements:
12 13 11 12 45 67 13 11 12 43
Enter an element to count: 12
OUTPUT:
The number of occurrences of 12 are: 3```

The steps required to count all occurrences of an element in an array are as follows:

1. Scan the size of array and elements of the array from user.
2. Scan the key element whose occurrences needed to be count from the array.
3. Set Count = 0.
4. Iterate over each element and check whether it is equal to key element or not. If element is key element, increment count as: Count = Count + 1.
5. Print the result as Count.

#### C++ Program to count all occurrences of an element in an array is as follows:

```/* Program to count all occurrences of an element in an array */
#include<bits/stdc++.h>
using namespace std;
int main()
{
/* Scan size of array */
int n;
cout<<"Enter the size of an array: ";
cin>>n;

/* Scan Array Elements */
int arr[n];
cout<<"\nEnter array elements:\n";
for(int i = 0; i < n; i++)
{
cin>>arr[i];
}

/* Scan key element */
int key;
cout<<"\nEnter key element: ";
cin>>key;

int count = 0;

/* Count occurence of key element in an array */
for(int i = 0; i < n; i++)
{
if(arr[i] == key)
count = count + 1;
}

/*Printing the result */
cout<<"\nThe number of occurences of "<<key<<" are: "<<count;
}

```
```OUTPUT:
Enter the size of an array:
Enter array elements:
1 3 2 3 5
Enter key element:
The number of occurences of 3 are: 2
Time Complexity:
O(n), where ‘n’ is the size of an element```

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