How to Find the Mode of Vector in C++?

How to Find the First Occurrence of an Element in a Vector?

How to Delete an Element from a Multiset in C++?

In C++, a vector is a dynamic array that resizes itself when needed. It also allows random access to its elements. In this article, we will learn how to find the mode of a vector in C++. The mode of a vector is the element that highest number of occurrences in the vector.

Example:

Input:
myVector = { 1, 2, 3, 4, 5, 2, 3, 2, 2, 4, 2 }

Output:
Mode : 2

Finding Mode of Vector in C++

We can find the mode of a vector in C++ using a std::map container to count the frequency of each element in the vector, and then find the element with the maximum frequency.

C++ Program for Finding Mode of Vector in C++

C++

// C++ Program to find mode of all Elements in a vector 
#include <iostream> 
#include <unordered_map> 
#include <vector> 
using namespace std; 
  
// Function to find the mode of a vector 
int findMode(const vector<int>& nums) 
{ 
    // Create an unordered map to store frequency of each 
    // element 
    unordered_map<int, int> frequency; 
  
    // Iterate through the vector and update frequency of 
    // each element 
    for (int num : nums) { 
        frequency[num]++; 
    } 
  
    // Initialize variables to keep track of mode and its 
    // frequency 
    int mode = 0; 
    int maxFrequency = 0; 
  
    // Iterate through the unordered map and find the 
    // element with maximum frequency 
    for (const auto& pair : frequency) { 
        if (pair.second > maxFrequency) { 
            maxFrequency = pair.second; 
            mode = pair.first; 
        } 
    } 
  
    // Return the mode 
    return mode; 
} 
  
// Driver Code 
int main() 
{ 
    // Create a vector of numbers 
    vector<int> numbers 
        = { 1, 2, 3, 4, 5, 2, 3, 2, 2, 4, 2 }; 
  
    // Find the mode of the vector 
    int mode = findMode(numbers); 
  
    // Print the mode 
    cout << "Mode: " << mode << endl; 
  
    return 0; 
}

Output

Mode: 2

Time complexity: O(N)
Space complexity: O(N)

Tags:

#CPP Examples #cpp-map #cpp-vector #STL #C++ #C++ Programs #CPP #STL

How to Find the First Occurrence of an Element in a Vector?

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How to Find the Mode of Vector in C++?

Finding Mode of Vector in C++

C++ Program for Finding Mode of Vector in C++

C++

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