Posted on by Kalkicode
Code Array

Find the smallest and second smallest element in an array

The problem at hand is to find the smallest and second smallest elements in an array of integers. This task involves iterating through the array and identifying the two smallest values present in it. This operation can be useful in various contexts, such as ranking students based on test scores or finding the lowest and second lowest prices in a dataset.

Problem Statement and Description

Given an array of integers, the objective is to determine the smallest and second smallest values present in the array. For example, consider the array [10, 3, 44, 86, 8, 9, 4, 5, 7]. The smallest element in this array is 3, and the second smallest element is 4.

Idea to Solve the Problem

To find the smallest and second smallest elements in the array, we can iterate through the array while keeping track of the two smallest values encountered so far. We'll initialize two variables, first and second, to store these values. As we traverse the array, we'll compare each element with these variables and update them accordingly. By the end of the iteration, we will have identified the smallest and second smallest elements.

Pseudocode

find_smallest(arr, size):
    if size < 2:
        return
    else:
        first = INT_MAX
        second = INT_MAX
        for i from 0 to size-1:
            if arr[i] < first:
                second = first
                first = arr[i]
            else if arr[i] < second:
                second = arr[i]
        
        print "First smallest: ", first
        print "Second smallest: ", second

Algorithm Explanation

  1. Check if the size of the array is less than 2. If so, there can't be a second smallest element, and we return.
  2. Initialize two variables, first and second, to INT_MAX. These will be used to store the smallest and second smallest elements.
  3. Iterate through the array. For each element arr[i]:
    • Compare arr[i] with first. If it's smaller than first, update second with the value of first and update first with the value of arr[i].
    • If arr[i] is not smaller than first but is smaller than second, update second with the value of arr[i].
  4. After the iteration, the first variable will contain the smallest element, and the second variable will contain the second smallest element.
  5. Print the values of first and second.

Program

//C Program 
//Find the smallest and second smallest element in an array
#include <stdio.h>

#include <limits.h>

void find_smallest(int arr[], int size)
{
	if (size < 2)
	{
		return;
	}
	else
	{
		//Variable which is used to store the result 
		int first = INT_MAX;
		int second = INT_MAX;
		for (int i = 0; i < size; i++)
		{
			//compare the array element values
			if (first > arr[i])
			{
				if (second > first)
				{
					second = first;
				}
				first = arr[i];
			}
			else if (second > arr[i])
			{
				second = arr[i];
			}
		}
		//Display result
		printf("First smallest : %d\n", first);
		printf("Second smallest  : %d\n", second);
	}
}
int main()
{
	//Define collection of array elements
	int arr[] = {
		10 , 3 , 44 , 86 , 8 , 9 , 4 , 5 , 7
	};
	//Get the size of array
	int size = sizeof(arr) / sizeof(arr[0]);
	find_smallest(arr, size);
	return 0;
}

Output

First smallest : 3
Second smallest  : 4
/*
  Java Program
  Find the smallest and second smallest element in an array
*/
class MyArray
{
	public void find_smallest(int[] arr, int size)
	{
		if (size <= 1)
		{
			return;
		}
		else
		{
			//Variable which is used to store the result 
			int first = Integer.MAX_VALUE;
			int second = Integer.MAX_VALUE;
			for (int i = 0; i < size; i++)
			{
				//compare the array element values
				if (first > arr[i])
				{
					if (second > first)
					{
						second = first;
					}
					first = arr[i];
				}
				else if (second > arr[i])
				{
					second = arr[i];
				}
			}
			//Display result
			System.out.print("First smallest : " + first + "\n");
			System.out.print("Second smallest  : " + second + "\n");
		}
	}
	public static void main(String[] args)
	{
		MyArray obj = new MyArray();
		//Define collection of array elements
		int[] arr = {
			10,
			3,
			44,
			86,
			8,
			9,
			4,
			5,
			7
		};
		//Get the size of array
		int size = arr.length;
		obj.find_smallest(arr, size);
	}
}

Output

First smallest : 3
Second smallest  : 4
//Include header file
#include <iostream>

#include<limits.h>

using namespace std;
/*
  C++ Program
  Find the smallest and second smallest element in an array
*/
class MyArray
{
	public: void find_smallest(int arr[], int size)
	{
		if (size <= 1)
		{
			return;
		}
		else
		{
			//Variable which is used to store the result 
			int first = INT_MAX;
			int second = INT_MAX;
			for (int i = 0; i < size; i++)
			{
				//compare the array element values
				if (first > arr[i])
				{
					if (second > first)
					{
						second = first;
					}
					first = arr[i];
				}
				else if (second > arr[i])
				{
					second = arr[i];
				}
			}
			//Display result
			cout << "First smallest : " << first << "\n";
			cout << "Second smallest  : " << second << "\n";
		}
	}
};
int main()
{
	MyArray obj = MyArray();
	int arr[] = {
		10 , 3 , 44 , 86 , 8 , 9 , 4 , 5 , 7
	};
	//Get the size of array
	int size = sizeof(arr) / sizeof(arr[0]);
	obj.find_smallest(arr, size);
	return 0;
}

Output

First smallest : 3
Second smallest  : 4
//Include namespace system
using System;
/*
  C# Program
  Find the smallest and second smallest element in an array
*/
class MyArray
{
	public void find_smallest(int[] arr, int size)
	{
		if (size <= 1)
		{
			return;
		}
		else
		{
			//Variable which is used to store the result 
			int first = int.MaxValue;
			int second = int.MaxValue;
			for (int i = 0; i < size; i++)
			{
				//compare the array element values
				if (first > arr[i])
				{
					if (second > first)
					{
						second = first;
					}
					first = arr[i];
				}
				else if (second > arr[i])
				{
					second = arr[i];
				}
			}
			//Display result
			Console.Write("First smallest : " + first + "\n");
			Console.Write("Second smallest  : " + second + "\n");
		}
	}
	public static void Main(String[] args)
	{
		MyArray obj = new MyArray();
		int[] arr = {
			10 , 3 , 44 , 86 , 8 , 9 , 4 , 5 , 7
		};
		//Get the size of array
		int size = arr.Length;
		obj.find_smallest(arr, size);
	}
}

Output

First smallest : 3
Second smallest  : 4
<?php
/*
  Php Program
  Find the smallest and second smallest element in an array
*/
class MyArray
{
	public	function find_smallest( $arr, $size)
	{
		if ($size <= 1)
		{
			return;
		}
		else
		{
			//Variable which is used to store the result 
			$first = PHP_INT_MAX;
			$second = PHP_INT_MAX;
			for ($i = 0; $i < $size; $i++)
			{
				//compare the array element values
				if ($first > $arr[$i])
				{
					if ($second > $first)
					{
						$second = $first;
					}
					$first = $arr[$i];
				}
				else if ($second > $arr[$i])
				{
					$second = $arr[$i];
				}
			}
			echo "First smallest : ". $first ."\n";
			echo "Second smallest  : ". $second ."\n";
		}
	}
}

function main()
{
	$obj = new MyArray();
	//Define collection of array elements
	$arr = array(10, 3, 44, 86, 8, 9, 4, 5, 7);
	//Get the size of array
	$size = count($arr);
	$obj->find_smallest($arr, $size);
}
main();

Output

First smallest : 3
Second smallest  : 4
/*
  Node Js Program
  Find the smallest and second smallest element in an array
*/
class MyArray
{
	find_smallest(arr, size)
	{
		if (size <= 1)
		{
			return;
		}
		else
		{
			//Variable which is used to store the result 
			var first = Number.MAX_VALUE;
			var second = Number.MAX_VALUE;
			for (var i = 0; i < size; i++)
			{
				//compare the array element values
				if (first > arr[i])
				{
					if (second > first)
					{
						second = first;
					}
					first = arr[i];
				}
				else if (second > arr[i])
				{
					second = arr[i];
				}
			}
			process.stdout.write("First smallest : " + first + "\n");
			process.stdout.write("Second smallest  : " + second + "\n");
		}
	}
}

function main()
{
	var obj = new MyArray();
	//Define collection of array elements
	var arr = [10, 3, 44, 86, 8, 9, 4, 5, 7];
	//Get the size of array
	var size = arr.length;
	obj.find_smallest(arr, size);
}
main();

Output

First smallest : 3
Second smallest  : 4
import sys
# 
#   Python 3 Program
#   Find the smallest and second smallest element in an array

class MyArray :
	def find_smallest(self, arr, size) :
		if (size <= 1) :
			return
		else :
			# Variable which is used to store the result 
			first = sys.maxsize
			second = sys.maxsize
			i = 0
			while (i < size) :
				# compare the array element values
				if (first > arr[i]) :
					if (second > first) :
						second = first
					
					first = arr[i]
				
				elif(second > arr[i]) :
					second = arr[i]
				
				i += 1
			
			print("First smallest : ", first )
			print("Second smallest  : ", second )
		
	

def main() :
	obj = MyArray()
	# Define collection of array elements
	arr = [10, 3, 44, 86, 8, 9, 4, 5, 7]
	# Get the size of array
	size = len(arr)
	obj.find_smallest(arr, size)

if __name__ == "__main__": main()

Output

First smallest :  3
Second smallest  :  4
#   Ruby Program
#   Find the smallest and second smallest element in an array

class MyArray

	def find_smallest(arr, size)
	
		if (size <= 1)
		
			return
		else
		
			# Variable which is used to store the result 
			first = (2 ** (0. size * 8 - 2))
			second = (2 ** (0. size * 8 - 2))
			i = 0
			while (i < size)
			
				# compare the array element values
				if (first > arr[i])
				
					if (second > first)
					
						second = first
					end
					first = arr[i]
				elsif(second > arr[i])
				
					second = arr[i]
				end
				i += 1
			end
			# Display result
			print("First smallest : ", first ,"\n")
			print("Second smallest  : ", second ,"\n")
		end
	end
end
def main()

	obj = MyArray.new()
	# Define collection of array elements
	arr = [10, 3, 44, 86, 8, 9, 4, 5, 7]
	# Get the size of array
	size = arr.length
	obj.find_smallest(arr, size)
end
main()

Output

First smallest : 3
Second smallest  : 4
/*
  Scala Program
  Find the smallest and second smallest element in an array
*/
class MyArray
{
	def find_smallest(arr: Array[Int], size: Int): Unit = {
		if (size <= 1)
		{
			return;
		}
		else
		{
			//Variable which is used to store the result 
			var first: Int = Int.MaxValue;
			var second: Int = Int.MaxValue;
			var i: Int = 0;
			while (i < size)
			{
				//compare the array element values
				if (first > arr(i))
				{
					if (second > first)
					{
						second = first;
					}
					first = arr(i);
				}
				else if (second > arr(i))
				{
					second = arr(i);
				}
				i += 1;
			}
			//Display result
			print("First smallest : " + first + "\n");
			print("Second smallest  : " + second + "\n");
		}
	}
}
object Main
{
	def main(args: Array[String]): Unit = {
		var obj: MyArray = new MyArray();
		//Define collection of array elements
		var arr: Array[Int] = Array(10, 3, 44, 86, 8, 9, 4, 5, 7);
		//Get the size of array
		var size: Int = arr.length;
		obj.find_smallest(arr, size);
	}
}

Output

First smallest : 3
Second smallest  : 4
/*
  Swift Program
  Find the smallest and second smallest element in an array
*/
class MyArray
{
	func find_smallest(_ arr: [Int], _ size: Int)
	{
		if (size <= 1)
		{
			return;
		}
		else
		{
			//Variable which is used to store the result 
			var first: Int = Int.max;
			var second: Int = Int.max;
			var i: Int = 0;
			while (i < size)
			{
				//compare the array element values
				if (first > arr[i])
				{
					if (second > first)
					{
						second = first;
					}
					first = arr[i];
				}
				else if (second > arr[i])
				{
					second = arr[i];
				}
				i += 1;
			}
			print("First smallest : ", first );
			print("Second smallest  : ", second );
		}
	}
}
func main()
{
	let obj: MyArray = MyArray();
	//Define collection of array elements
	let arr: [Int] = [10, 3, 44, 86, 8, 9, 4, 5, 7];
	//Get the size of array
	let size: Int = arr.count;
	obj.find_smallest(arr, size);
}
main();

Output

First smallest :  3
Second smallest  :  4

Time Complexity Analysis

The algorithm iterates through the array once, performing constant-time comparisons and updates for each element. Therefore, the time complexity of the algorithm is O(n), where n is the size of the input array. This linear time complexity ensures that the algorithm performs well even for larger input arrays.

Comment

Please share your knowledge to improve code and content standard. Also submit your doubts, and test case. We improve by your feedback. We will try to resolve your query as soon as possible.

New Comment