# Find the largest three elements in an array

Given an array with all distinct elements, find the largest three elements. Expected time complexity is O(n) and extra space is O(1).

Examples :

```Input: arr[] = {10, 4, 3, 50, 23, 90}
Output: 90, 50, 23
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Below is algorithm:

```1) Initialize the largest three elements as minus infinite.
first = second = third = -∞

2) Iterate through all elements of array.
a) Let current array element be x.
b) If (x > first)
{
// This order of assignment is important
third = second
second = first
first = x
}
c)  Else if (x > second)
{
third = second
second = x
}
d)  Else if (x > third)
{
third = x
}

3) Print first, second and third.
```

Below is the implementation of above algorithm.

## C

 `#include ` `#include /* For INT_MIN */ ` `  `  `/* Function to print three largest elements */` `void` `print3largest(``int` `arr[], ``int` `arr_size) ` `{ ` `    ``int` `i, first, second, third; ` `  `  `    ``/* There should be atleast three elements */` `    ``if` `(arr_size < 3) ` `    ``{ ` `        ``printf``(``" Invalid Input "``); ` `        ``return``; ` `    ``} ` `  `  `    ``third = first = second = INT_MIN; ` `    ``for` `(i = 0; i < arr_size ; i ++) ` `    ``{ ` `        ``/* If current element is greater than first*/` `        ``if` `(arr[i] > first) ` `        ``{ ` `            ``third = second; ` `            ``second = first; ` `            ``first = arr[i]; ` `        ``} ` `  `  `        ``/* If arr[i] is in between first and second then update second  */` `        ``else` `if` `(arr[i] > second) ` `        ``{ ` `            ``third = second; ` `            ``second = arr[i]; ` `        ``} ` `  `  `        ``else` `if` `(arr[i] > third) ` `            ``third = arr[i]; ` `    ``} ` `  `  `    ``printf``(````"Three largest elements are %d %d %d "````, first, second, third); ` `} ` `  `  `  `  `/* Driver program to test above function */` `int` `main() ` `{ ` `    ``int` `arr[] = {12, 13, 1, 10, 34, 1}; ` `    ``int` `n = ``sizeof``(arr)/``sizeof``(arr); ` `    ``print3largest(arr, n); ` `    ``return` `0; ` `} ` `/*This code is edited by Ayush Singla(@ayusin51)*/`

## Java

 `// Java code to find largest three elements ` `// in an array ` ` `  `class` `PrintLargest ` `{ ` `    ``/* Function to print three largest elements */` `    ``static` `void` `print3largest(``int` `arr[], ``int` `arr_size) ` `    ``{ ` `        ``int` `i, first, second, third; ` `   `  `        ``/* There should be atleast three elements */` `        ``if` `(arr_size < ``3``) ` `        ``{ ` `            ``System.out.print(``" Invalid Input "``); ` `            ``return``; ` `        ``} ` `       `  `        ``third = first = second = Integer.MIN_VALUE; ` `        ``for` `(i = ``0``; i < arr_size ; i ++) ` `        ``{ ` `            ``/* If current element is greater than ` `            ``first*/` `            ``if` `(arr[i] > first) ` `            ``{ ` `                ``third = second; ` `                ``second = first; ` `                ``first = arr[i]; ` `            ``} ` `       `  `            ``/* If arr[i] is in between first and ` `            ``second then update second  */` `            ``else` `if` `(arr[i] > second) ` `            ``{ ` `                ``third = second; ` `                ``second = arr[i]; ` `            ``} ` `       `  `            ``else` `if` `(arr[i] > third) ` `                ``third = arr[i]; ` `        ``} ` `       `  `        ``System.out.println(``"Three largest elements are "` `+ ` `                       ``first + ``" "` `+ second + ``" "` `+ third); ` `    ``} ` ` `  `    ``/* Driver program to test above function*/` `    ``public` `static` `void` `main (String[] args) ` `    ``{ ` `        ``int` `arr[] = {``12``, ``13``, ``1``, ``10``, ``34``, ``1``}; ` `        ``int` `n = arr.length; ` `        ``print3largest(arr, n); ` `    ``} ` `} ` `/*This code is contributed by Prakriti Gupta  ` `and edited by Ayush Singla(@ayusin51)*/`

## Python3

 `# Python3 code to find largest three ` `# elements in an array ` `import` `sys ` ` `  `# Function to print three largest  ` `# elements  ` `def` `print3largest(arr, arr_size): ` ` `  `    ``# There should be atleast three ` `    ``# elements  ` `    ``if` `(arr_size < ``3``): ` `     `  `        ``print``(``" Invalid Input "``) ` `        ``return` `     `  `    ``third ``=` `first ``=` `second ``=` `-``sys.maxsize ` `     `  `    ``for` `i ``in` `range``(``0``, arr_size): ` `     `  `        ``# If current element is greater ` `        ``# than first ` `        ``if` `(arr[i] > first): ` `         `  `            ``third ``=` `second ` `            ``second ``=` `first ` `            ``first ``=` `arr[i] ` `         `  ` `  `        ``# If arr[i] is in between first ` `        ``# and second then update second  ` `        ``elif` `(arr[i] > second): ` `         `  `            ``third ``=` `second ` `            ``second ``=` `arr[i] ` `         `  `        ``elif` `(arr[i] > third): ` `            ``third ``=` `arr[i] ` `     `  `    ``print``(``"Three largest elements are"``, ` `                  ``first, second, third) ` ` `  `# Driver program to test above function  ` `arr ``=` `[``12``, ``13``, ``1``, ``10``, ``34``, ``1``] ` `n ``=` `len``(arr) ` `print3largest(arr, n) ` ` `  `# This code is contributed by Smitha Dinesh Semwal  ` `# and edited by Ayush Singla(@ayusin51). `

## C#

 `// C# code to find largest  ` `// three elements in an array ` `using` `System; ` ` `  `class` `PrintLargest ` `{ ` `     `  `    ``// Function to print three  ` `    ``// largest elements ` `    ``static` `void` `print3largest(``int``[] arr, ` `                              ``int` `arr_size) ` `    ``{ ` `        ``int` `i, first, second, third; ` `     `  `        ``// There should be atleast three elements ` `        ``if` `(arr_size < 3) ` `        ``{ ` `            ``Console.WriteLine(``"Invalid Input"``); ` `            ``return``; ` `        ``} ` `         `  `        ``third = first = second = 000; ` `        ``for` `(i = 0; i < arr_size ; i ++) ` `        ``{ ` `            ``// If current element is  ` `            ``// greater than first ` `            ``if` `(arr[i] > first) ` `            ``{ ` `                ``third = second; ` `                ``second = first; ` `                ``first = arr[i]; ` `            ``} ` `         `  `            ``// If arr[i] is in between first ` `            ``// and second then update second ` `            ``else` `if` `(arr[i] > second) ` `            ``{ ` `                ``third = second; ` `                ``second = arr[i]; ` `            ``} ` `         `  `            ``else` `if` `(arr[i] > third) ` `                ``third = arr[i]; ` `        ``} ` `         `  `        ``Console.WriteLine(``"Three largest elements are "` `+ ` `                           ``first + ``" "` `+ second + ` `                           ``" "` `+ third); ` `    ``} ` ` `  `    ``// Driver code ` `    ``public` `static` `void` `Main () ` `    ``{ ` `        ``int``[] arr = ``new` `int``[] {12, 13, 1, 10, 34, 1}; ` `        ``int` `n = arr.Length; ` `        ``print3largest(arr, n); ` `    ``} ` `} ` ` `  `// This code is contributed by KRV and edited by Ayush Singla(@ayusin51).  `

## PHP

 ` ``\$first``) ` `        ``{ ` `            ``\$third` `= ``\$second``; ` `            ``\$second` `= ``\$first``; ` `            ``\$first` `= ``\$arr``[``\$i``]; ` `        ``} ` ` `  `        ``// If arr[i] is in between first  ` `        ``// and second then update second  ` `        ``else` `if` `(``\$arr``[``\$i``] > ``\$second``) ` `        ``{ ` `            ``\$third` `= ``\$second``; ` `            ``\$second` `= ``\$arr``[``\$i``]; ` `        ``} ` ` `  `        ``else` `if` `(``\$arr``[``\$i``] > ``\$third``) ` `            ``\$third` `= ``\$arr``[``\$i``]; ` `    ``} ` ` `  `    ``echo` `"Three largest elements are "``,  ` `       ``\$first``,``" "``, ``\$second``,``" "``, ``\$third``; ` `} ` ` `  ` `  `// Driver Code ` `\$arr` `= ``array``(12, 13, 1,  ` `             ``10, 34, 1); ` `\$n` `= ``count``(``\$arr``); ` `print3largest(``\$arr``, ``\$n``); ` ` `  `// This code is contributed by anuj_67 and edited by Ayush Singla(@ayusin51). ` `?> `

Output :

`Three largest elements are 34 13 12`

Another approach:An efficient way to solve this problem is to use any O(nLogn) sorting algorithm & simply returning the last 3 largest elements .

## C++

 `// C++ code to find largest  ` `// three elements in an array ` `#include ` `using` `namespace` `std; ` ` `  `void` `find3largest(``int` `arr[], ``int` `n) ` `{ ` `    ``sort(arr, arr + n); ``//It uses Tuned Quicksort with  ` `                    ``//avg. case Time complexity = O(nLogn) ` `         `  `    ``int` `check = 0, count = 1; ` `         `  `    ``for``(``int` `i = 1; i <= n; i++) ` `    ``{ ` `             `  `        ``if``(count<4) ` `        ``{ ` `            ``if``(check != arr[n - i])  ` `            ``{  ` `                ``// to handle duplicate values ` `                ``cout << arr[n - i] << ``" "``; ` `                ``check = arr[n - i]; ` `                ``count++; ` `            ``} ` `        ``} ` `        ``else` `            ``break``; ` `    ``} ` `} ` `     `  `// Driver code ` `int` `main() ` `{ ` `    ``int` `arr[] = {12, 45, 1, -1, 45, 54, 23, 5, 0, -10}; ` `    ``int` `n = ``sizeof``(arr)/``sizeof``(arr); ` `    ``find3largest(arr, n); ` `} ` ` `  `// This code is contibuted by Rajput-Ji `

## Java

 `// Java code to find largest  ` `// three elements in an array ` ` `  ` `  `import` `java.io.*; ` `import` `java.util.Arrays; ` ` `  `class` `GFG { ` `     ``void` `find3largest(``int``[] arr) ` `    ``{ ` `        ``Arrays.sort(arr); ``//It uses Tuned Quicksort with  ` `                         ``//avg. case Time complexity = O(nLogn) ` `        ``int` `n = arr.length; ` `        ``int` `check = ``0``, count = ``1``; ` `         `  `        ``for``(``int` `i = ``1``; i <= n; i++){ ` `             `  `            ``if``(count<``4``){ ` `                ``if``(check!=arr[n-i])  ` `                ``{  ` `                   ``// to handle duplicate values ` `                    ``System.out.print(arr[n-i]+``" "``); ` `                    ``check = arr[n-i]; ` `                    ``count++; ` `                ``} ` `            ``} ` `             ``else`  `                ``break``; ` `        ``} ` `         `  `    ``} ` `     `  `   ``// Driver code ` `    ``public` `static` `void` `main(String[] args) ` `    ``{ ` `        ``GFG obj = ``new` `GFG(); ` `        ``int``[] arr={``12``,``45``,``1``,-``1``,``45``,``54``,``23``,``5``,``0``,-``10``}; ` `        ``obj.find3largest(arr); ` `    ``} ` `     `  `} ` `//This code is contibuted by Prashant Malik `

Output :

` 54 45 23 `