# Print all the Repeated Numbers with Frequency in an Array in C++

In this tutorial, we will learn how to print the repeated numbers with frequency in an array in C++. Before proceeding further First, Let’s understand the problem. What do you mean by repeated numbers?

Repeated Numbers: are the numbers who have occurred more than one time.

for example: In Set `A= {3, 7, 2, 3, 9, 2, 3,3}`

Elements 2 and 3 are repeated numbers. because they have occurred more than one time.

(*Note: We should not print the frequency of all the numbers in an array. We should print the frequency of only repeated numbers in an array.)

Frequency: refers to the no. of occurrences.

for example: In Set `A= {3, 7, 2, 3, 9, 2, 3,3}`

The frequency of element 3 is 4 (because the no of occurrences of element 3 in the given set is 4).

Similarly,

The frequency of elements 7, 2, 9 will be 1, 2, 1 respectively.

Now, let’s see the code for “Print all the Repeated Numbers with Frequency in an Array in C++”.

## Program to print all the repeated numbers with frequency in an array in C++

```#include<bits/stdc++.h>
using namespace std;
int main()
{
int i,j,n,count;

// 'n' will contain the no. of elements.
cout<<"Enter no. of elements:";
cin>>n;

// 'set[n]' will contain all the entered elements. 'set[n]' is an array of size n (as, we want to store only n elements).
// Avoid writing set or set etc. By writing this we are wasting computer memory, use only that much amount of space which is required.

int set[n];
cout<<"\nEnter the elements:";
for(i=0; i<n; i++)
{
cin>>set[i];
}

/* we want to print only 1 entry of repeated number. For this purpose, we have used 'flag[n]'. If flag[j] is equal to 1 then it means, we have already considered set[j] element for counting the frequency of a repeated number. If flag[j] is equal to 0 then it means we haven't considered set[j] element for counting the frequency of a repeated number.*/
int flag[n]={0};          // Here, we have initialized all the blocks of the 'flag' array with 0.
cout<<"\nRepeated Numbers with their frequency:";
for(i=0; i<n; i++)
{
count=0;
if(flag[i]!=1)       // if element set[i] is not considered for counting the frequency of a repeated number
{
for(j=0; j<n; j++)
{
if(set[i]==set[j])
{
count++;
flag[j]=1;     // set flag[j] to 1, to avoid more than 1 entry of repeated number in the output
}
}
if(count>1)      // if no. of occurrences of element set[i] > 1 (or if the element set[i] is repeated number)
{
cout<<"\n"<<set[i]<<" -> "<<count;
}
}
}
return 0;
}```

Input/Output:

```Enter no. of elements:10
Enter the elements:4 7 6 4 8 4 7 2 1 1
Repeated Numbers with their frequency:
4 -> 3
7 -> 2
1 -> 2

```

#### Time Complexity:

O(n^2), Where n is equal to no. of elements in the array.