# Program to find largest element in an array

Hello Everyone,

Given an array, find the largest element in it.
Example:

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

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

The solution is to initialize max as first element, then traverse the given array from second element till end. For every traversed element, compare it with max, if it is greater than max, then update max.

`// 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;`

`}`

Output:

Largest in given array is 9808

Using Library Function :
We use std::max_element in 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;`

`}`

Output :

9808

Time complexity of the above solution is Theta(n) .