Program to find largest element in an array

Given an array arr of size N, the task is to find the largest element in the given array. 

Example:

Input: arr[] = {10, 20, 4}
Output: 20

Input : arr[] = {20, 10, 20, 4, 100}
Output : 100

Approach 1 – Linear Traversal: One of the most simplest and basic approach to solve this problem is to simply traverse the whole list and find the maximum among them. 

Follow the steps below to implement this idea:

• Create a local variable max to store the maximum among the list
• Initialize max with the first element initially, to start the comparison.
• Then traverse the given array from second element till end, and for each element:
  • Compare the current element with max
  • If the current element is greater than max, then replace the value of max with the current element.
• At the end, return and print the value of the largest element of array stored in max.

Below is the implementation of the above approach: 

C++

// C++ program to find maximum
// in arr[] of size n
#include <bits/stdc++.h>
using namespace std;

int largest(int arr[], int n)
{
    int i;

    // Initialize maximum element
    int max = arr[0];

    // Traverse array elements
    // from second and compare
    // every element with current max
    for (i = 1; i < n; i++)
        if (arr[i] > max)
            max = arr[i];

    return max;
}

// Driver Code
int main()
{
    int arr[] = {10, 324, 45, 90, 9808};
    int n = sizeof(arr) / sizeof(arr[0]);
    cout << "Largest in given array is "
         << largest(arr, n);
    return 0;
}

// This Code is contributed
// by Shivi_Aggarwal

C

// C program to find maximum in arr[] of size n
#include <stdio.h>

// C function to find maximum in arr[] of size n
int largest(int arr[], int n)
{
    int i;

    // Initialize maximum element
    int max = arr[0];

    // Traverse array elements from second and
    // compare every element with current max
    for (i = 1; i < n; i++)
        if (arr[i] > max)
            max = arr[i];

    return max;
}

int main()
{
    int arr[] = {10, 324, 45, 90, 9808};
    int n = sizeof(arr)/sizeof(arr[0]);
    printf("Largest in given array is %d", largest(arr, n));
    return 0;
}

Java

// Java Program to find maximum in arr[]
class Test
{
     static int arr[] = {10, 324, 45, 90, 9808};

     // Method to find maximum in arr[]
     static int largest()
     {
         int i;

         // Initialize maximum element
         int max = arr[0];

         // Traverse array elements from second and
         // compare every element with current max
         for (i = 1; i < arr.length; i++)
             if (arr[i] > max)
                 max = arr[i];

         return max;
     }

     // Driver method
     public static void main(String[] args)
     {
         System.out.println("Largest in given array is " + largest());
        }
 }

Python3

# Python3 program to find maximum
# in arr[] of size n

# Function to find maximum
# in arr[] of size n
def largest(arr,n):
   # Initialize maximum element
   mx = arr[0]

   # Traverse array elements from second
   # and compare every element with
   # current max
   for i in range(1, n):
     if arr[i] > mx:
         mx = arr[i]

   return mx

# Driver Code
arr = [10, 324, 45, 90, 9808]
n = len(arr)

#calculating length of an array
Ans = largest(arr,n)

# display max
print ("Largest in given array is",Ans)

# This code is contributed by Jai Parkash Bhardwaj
# and improved by prophet1999

C#

// C# Program to find maximum in arr[]
using System;

class GFG {

    static int []arr = {10, 324, 45, 90, 9808};

    // Method to find maximum in arr[]
    static int largest()
    {
        int i;

        // Initialize maximum element
        int max = arr[0];

        // Traverse array elements from second and
        // compare every element with current max
        for (i = 1; i < arr.Length; i++)
            if (arr[i] > max)
                max = arr[i];

        return max;
    }

    // Driver method
    public static void Main()
    {
        Console.WriteLine("Largest in given "
                  + "array is " + largest());
    }
}

// This code is contributed by anuj_67.

PHP

<?php
// PHP program to find maximum
// in arr[] of size n

// PHP function to find maximum
// in arr[] of size n
function largest($arr, $n)
{
    $i;

    // Initialize maximum element
    $max = $arr[0];

    // Traverse array elements
    // from second and
    // compare every element
    // with current max
    for ($i = 1; $i < $n; $i++)
        if ($arr[$i] > $max)
            $max = $arr[$i];

    return $max;
}

    // Driver Code
    $arr= array(10, 324, 45, 90, 9808);
    $n = sizeof($arr);
    echo "Largest in given array is "
                 , largest($arr, $n);

// This code is contributed by aj_36
?>

Javascript

<script>

// JavaScript program to find
// maximum in arr[] of size n

    function largest(arr) {
        let i;

        // Initialize maximum element
        let max = arr[0];

        // Traverse array elements
        // from second and compare
        // every element with current max
        for (i = 1; i < arr.length; i++) {
            if (arr[i] > max)
                max = arr[i];
        }

      return max;
}

    // Driver code
    let arr = [10, 324, 45, 90, 9808];
    document.write("Largest in given array is " + largest(arr));

 // This code is contributed by Surbhi Tyagi

</script>

Output

Largest in given array is 9808

Time complexity: O(N), to traverse the Array completely.
Auxiliary Space: O(1), as only an extra variable is created, which will take O(1) space.

Approach 2: Using Library Function: Most of the languages have a relevant max() type in-built function to find the maximum element, such as  std::max_element in C++. We can use this function to directly find the maximum element. 

Below is the implementation of the above approach: 

C++

// C++ program to find maximum in arr[] of size n
#include <bits/stdc++.h>
using namespace std;

// returns maximum in arr[] of size n
int largest(int arr[], int n)
{
    return *max_element(arr, arr+n);
}

int main()
{
    int arr[] = {10, 324, 45, 90, 9808};
    int n = sizeof(arr)/sizeof(arr[0]);
    cout << largest(arr, n);
    return 0;
}

Java

// Java program to
// find maximum in
// arr[] of size n
import java .io.*;
import java.util.*;

class GFG
{

    // returns maximum in
    // arr[] of size n
    static int largest(int []arr,
                       int n)
    {
        Arrays.sort(arr);
        return arr[n - 1];
    }

    // Driver code
    static public void main (String[] args)
    {
        int []arr = {10, 324, 45,
                     90, 9808};
        int n = arr.length;
        System.out.println(largest(arr, n));
    }
}

// This code is contributed
// by anuj_67.

Python3

# Python 3 program to find
# maximum in arr[] of size n

# returns maximum
# in arr[] of size n
def largest(arr, n):

    return max(arr)

# driver code
arr = [10, 324, 45, 90, 9808]
n = len(arr)

print(largest(arr, n))

# This code is contributed by
# Smitha Dinesh Semwal

C#

// C# program to find maximum in
// arr[] of size n
using System;
using System.Linq;

public class GFG {

    // returns maximum in arr[]
    static int Largest(int[] arr)
    {
        return arr.Max();
    }

    // Driver code
    static public void Main ()
    {
        int[] arr = {10, 324, 45, 90, 9808};
        Console.WriteLine(Largest(arr));
    }
}

// This code is contributed by anuj_67.
// Minor code cleanup by shanmukha7

PHP

<?php
// PHP program to find maximum
// in arr[] of size n

// returns maximum in
// arr[] of size n
function largest( $arr, $n)
{
    return max($arr);
}

    // Driver COde
    $arr = array(10, 324, 45, 90, 9808);
    $n = count($arr);
    echo largest($arr, $n);

// This code is contributed by anuj_67.
?>

Javascript

<script>

// Javascript program to find maximum in arr[] of size n

// returns maximum in arr[] of size n
function largest(arr, n)
{
    arr.sort();
    return arr[n-1];
}

    let arr = [10, 324, 45, 90, 9808];
    let n = arr.length;
    document.write(largest(arr, n));


//This code is contributed by Mayank Tyagi

</script>

Output

9808

Time complexity: O(N), since the in-built max_element() function takes O(N) time.
Auxiliary Space: O(1), as only an extra variable is created, which will take O(1) space.

Refer below article for more methods: Program to find the minimum (or maximum) element of an array