How to Find Minimum and Maximum Element of an Array Using STL in C++?

Given an array of n elements, the task is to find the minimum and maximum element of array using STL in C++.

Examples

Input: arr[] = {1, 45, 54, 7, 76}
Output: min = 1, max = 76
Explanation: 1 is the smallest and 76 is the largest among all elements.

Input: arr[] = {10, 7, 5, 4, 6}
Output: min = 4, max = 10
Explanation: 4 is the smallest and 10 is the largest among all elements.

STL provides two different ways to find the minimum and maximum element of array in C++:

Using min_element() and max_element()

C++ STL provides two function std::min_element() and std::max_element() to find the minimum element and the maximum element in the given range. We can use these functions to find the smallest and largest element of the array.

Syntax

std::min_element(arr, arr + n);
std::max_element(arr, arr + n);

where, arr is the name of the array and n is the number of elements in it.

Example

// C++ program to find the min and max
// element of an array using min_element()
// and max_element()
#include <bits/stdc++.h>
using namespace std;

int main() {
    int arr[] = {1, 45, 54, 71, 76};
    int n = sizeof(arr) / sizeof(arr[0]);

    // Find the min element
    int min = *min_element(arr, arr + n);

    // Find the max element
    int max = *max_element(arr, arr + n);

    cout << "Min: " << min << endl;
    cout << "Max: " << max;
    return 0;
}

Min: 1
Max: 76

Time Complexity: O(n), where n is the number of elements in array.
Auxiliary Space: O(1)

Using minmax_element()

C++ STL also provides the std::minmax_element() function that is used to find both the minimum and the maximum element in the range in a single function call. This function returns a reference of std::pair object in which pair::first is the minimum element and pair::second is the maximum element.

Syntax

std::minmax_element(arr, arr + n);

where, arr is the name of the array and n is the number of elements in it.

Example

// C++ program to find the min and max element
// of an array using minmax_element()
#include <bits/stdc++.h>
using namespace std;

int main() {
    int arr[] = { 1, 45, 54, 71, 76};
    int n = sizeof(arr)/sizeof(arr[0]);
   
    // Finding minimum and maximum element
    auto minmax = minmax_element(arr,
                                 arr + n);
  
    cout << "Min: " << *minmax.first << endl;
    cout << "Max: " << *minmax.second;
    return 0;
}

Min: 1
Max: 76

Time Complexity: O(n), where n is the number of elements in array.
Auxiliary Space: O(1)