Find The Most Frequent Element in an Array
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Finding the most frequently occurring element in an array is a common array operation with multiple applications. For instance, it can be used to determine:
-
The most common marks scored by a class in a subject.
-
The mode of ungrouped data.
This program can be implemented either with or without functions, but using functions improves modularity.
Algorithm
1. Input the array size from the user.
2. Input the array elements.
3. Define a function frequent_element that takes the array and its size as parameters.
4. Use nested loops to:
- Count occurrences of each element.
- Track the maximum occurrence count.
5. Check if multiple elements have the same maximum frequency.
6. Print the result(s).
Code
#include <bits/stdc++.h>
using namespace std;
void frequent_element(int arr[], int n) {
int max_count = 0;
// Find the maximum occurrence count
for (int i = 0; i < n; i++) {
int count = 1;
for (int j = i + 1; j < n; j++) {
if (arr[i] == arr[j]) count++;
}
if (count > max_count) max_count = count;
}
// Print all elements with max_count occurrences
cout << "\nMost frequent number(s): ";
for (int i = 0; i < n; i++) {
int count = 1;
for (int j = i + 1; j < n; j++) {
if (arr[i] == arr[j]) count++;
}
if (count == max_count) {
cout << arr[i] << " ";
}
}
cout << endl;
}
int main() {
int arr[100], n;
cout << "Enter array size: ";
cin >> n;
cout << "Enter array elements:\n";
for (int i = 0; i < n; i++) {
cout << "Element " << i + 1 << ": ";
cin >> arr[i];
}
cout << "Original array: ";
for (int i = 0; i < n; i++) {
cout << arr[i] << " ";
}
frequent_element(arr, n);
return 0;
}
Output
Enter array size: 8
Enter array elements:
Element 1: 3
Element 2: 43
Element 3: 2
Element 4: 3
Element 5: 21
Element 6: 3
Element 7: 43
Element 8: 5
Original array: 3 43 2 3 21 3 43 5
Most frequent number(s): 3
Finding the Mode of Ungrouped Data
Mode is a measure of central tendency that identifies the most frequently occurring value in a dataset, particularly useful for categorical data.
Code
#include <bits/stdc++.h>
using namespace std;
void find_mode(int arr[], int n) {
int max_count = 0;
// Find maximum frequency
for (int i = 0; i < n; i++) {
int count = 1;
for (int j = i + 1; j < n; j++) {
if (arr[i] == arr[j]) count++;
}
if (count > max_count) max_count = count;
}
// Print all modes
cout << "\nMode(s): ";
for (int i = 0; i < n; i++) {
int count = 1;
for (int j = i + 1; j < n; j++) {
if (arr[i] == arr[j]) count++;
}
if (count == max_count) {
cout << arr[i] << " ";
}
}
cout << endl;
}
int main() {
int arr[100], n;
cout << "Enter data size: ";
cin >> n;
cout << "Enter data elements:\n";
for (int i = 0; i < n; i++) {
cout << "[" << i << "]: ";
cin >> arr[i];
}
cout << "Entered data: ";
for (int i = 0; i < n; i++) {
cout << arr[i] << " ";
}
find_mode(arr, n);
return 0;
}
Output
Enter data size: 8
Enter data elements:
[0]: 45
[1]: 32
[2]: 34
[3]: 26
[4]: 55
[5]: 41
[6]: 55
[7]: 27
Entered data: 45 32 34 26 55 41 55 27
Mode(s): 55
Summary
We demonstrated how to find the most frequent element in an array using basic search operations. The same logic was extended to calculate the mode of ungrouped data. This approach efficiently handles categorical data analysis.
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