find the most frequent element

# Python3 program to find the most  
# frequent element in an array. 
import math as mt 
  
def mostFrequent(arr, n): 
  
    # Insert all elements in Hash. 
    Hash = dict() 
    for i in range(n): 
        if arr[i] in Hash.keys(): 
            Hash[arr[i]] += 1
        else: 
            Hash[arr[i]] = 1
  
    # find the max frequency 
    max_count = 0
    res = -1
    for i in Hash:  
        if (max_count < Hash[i]):  
            res = i 
            max_count = Hash[i] 
          
    return res 
  
# Driver Code 
arr = [ 1, 5, 2, 1, 3, 2, 1]  
n = len(arr) 
print(mostFrequent(arr, n)) 

// CPP program to find the most frequent element 
// in an array. 
#include <bits/stdc++.h> 
using namespace std; 
  
int mostFrequent(int arr[], int n) 
{ 
    // Sort the array 
    sort(arr, arr + n); 
  
    // find the max frequency using linear traversal 
    int max_count = 1, res = arr[0], curr_count = 1; 
    for (int i = 1; i < n; i++) { 
        if (arr[i] == arr[i - 1]) 
            curr_count++; 
        else { 
            if (curr_count > max_count) { 
                max_count = curr_count; 
                res = arr[i - 1]; 
            } 
            curr_count = 1; 
        } 
    } 
  
    // If last element is most frequent 
    if (curr_count > max_count) 
    { 
        max_count = curr_count; 
        res = arr[n - 1]; 
    } 
  
    return res; 
} 
  
// driver program 
int main() 
{ 
    int arr[] = { 1, 5, 2, 1, 3, 2, 1 }; 
    int n = sizeof(arr) / sizeof(arr[0]); 
    cout << mostFrequent(arr, n); 
    return 0; 
}