# 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[50] or set[100] 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.

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very helpful for beginners very good approach