Find the first, second and third minimum elements in an array
Find the first, second and third minimum elements in an array in O(n).
Examples:
Input : 9 4 12 6
Output : First min = 4
Second min = 6
Third min = 9
Input : 4 9 1 32 12
Output : First min = 1
Second min = 4
Third min = 9
First approach : First we can use normal method that is sort the array and then print first, second and third element of the array. Time complexity of this solution is O(n Log n).
Second approach : Time complexity of this solution is O(n).
Algorithm-
First take an element
then if array[index] < Firstelement
Thirdelement = Secondelement
Secondelement = Firstelement
Firstelement = array[index]
else if array[index] < Secondelement
Thirdelement = Secondelement
Secondelement = array[index]
else if array[index] < Thirdelement
Thirdelement = array[index]
then print all the element
C++
// CPP program to find the first, second // and third minimum element in an array #include<bits/stdc++.h> #define MAX 100000 using namespace std; int Print3Smallest(int array[], int n) { int firstmin = MAX, secmin = MAX, thirdmin = MAX; for (int i = 0; i < n; i++) { /* Check if current element is less than firstmin, then update first, second and third */ if (array[i] < firstmin) { thirdmin = secmin; secmin = firstmin; firstmin = array[i]; } /* Check if current element is less than secmin then update second and third */ else if (array[i] < secmin) { thirdmin = secmin; secmin = array[i]; } /* Check if current element is less than then update third */ else if (array[i] < thirdmin) thirdmin = array[i]; } cout << "First min = " << firstmin << "\n"; cout << "Second min = " << secmin << "\n"; cout << "Third min = " << thirdmin << "\n"; } // Driver code int main() { int array[] = {4, 9, 1, 32, 12}; int n = sizeof(array) / sizeof(array[0]); Print3Smallest(array, n); return 0; } |
Java
// Java program to find the first, second // and third minimum element in an array import java.util.*; public class GFG { static void Print3Smallest(int array[], int n) { int firstmin = Integer.MAX_VALUE; int secmin = Integer.MAX_VALUE; int thirdmin = Integer.MAX_VALUE; for (int i = 0; i < n; i++) { /* Check if current element is less than firstmin, then update first, second and third */ if (array[i] < firstmin) { thirdmin = secmin; secmin = firstmin; firstmin = array[i]; } /* Check if current element is less than secmin then update second and third */ else if (array[i] < secmin) { thirdmin = secmin; secmin = array[i]; } /* Check if current element is less than then update third */ else if (array[i] < thirdmin) thirdmin = array[i]; } System.out.println("First min = " + firstmin ); System.out.println("Second min = " + secmin ); System.out.println("Third min = " + thirdmin ); } // Driver code public static void main(String[] args) { int array[] = {4, 9, 1, 32, 12}; int n = array.length; Print3Smallest(array, n); } } // This code is contributed by // Sam007 |
Python3
# A Python program to find the first, # second and third minimum element # in an array MAX = 100000 def Print3Smallest(arr, n): firstmin = MAX secmin = MAX thirdmin = MAX for i in range(0, n): # Check if current element # is less than firstmin, # then update first,second # and third if arr[i] < firstmin: thirdmin = secmin secmin = firstmin firstmin = arr[i] # Check if current element is # less than secmin then update # second and third elif arr[i] < secmin: thirdmin = secmin secmin = arr[i] # Check if current element is # less than,then upadte third elif arr[i] < thirdmin: thirdmin = arr[i] print("First min = ", firstmin) print("Second min = ", secmin) print("Third min = ", thirdmin) # driver program arr = [4, 9, 1, 32, 12] n = len(arr) Print3Smallest(arr, n) # This code is contributed by Shrikant13. |
C#
// C# program to find the first, second // and third minimum element in an array using System; class GFG { static void Print3Smallest(int []array, int n) { int firstmin = int.MaxValue; int secmin = int.MaxValue; int thirdmin = int.MaxValue; for (int i = 0; i < n; i++) { /* Check if current element is less than firstmin, then update first, second and third */ if (array[i] < firstmin) { thirdmin = secmin; secmin = firstmin; firstmin = array[i]; } /* Check if current element is less than secmin then update second and third */ else if (array[i] < secmin) { thirdmin = secmin; secmin = array[i]; } /* Check if current element is less than then update third */ else if (array[i] < thirdmin) thirdmin = array[i]; } Console.WriteLine("First min = " + firstmin ); Console.WriteLine("Second min = " + secmin ); Console.WriteLine("Third min = " + thirdmin ); } // Driver code static void Main() { int []array = new int[]{4, 9, 1, 32, 12}; int n = array.Length; Print3Smallest(array, n); } } // This code is contributed by Sam007 |
PHP
<?php // php program to find the first, second // and third minimum element in an array function Print3Smallest($array, $n) { $MAX = 100000; $firstmin = $MAX; $secmin = $MAX; $thirdmin = $MAX; for ($i = 0; $i < $n; $i++) { /* Check if current element is less than firstmin, then update first, second and third */ if ($array[$i] < $firstmin) { $thirdmin = $secmin; $secmin = $firstmin; $firstmin = $array[$i]; } /* Check if current element is less than secmin then update second and third */ else if ($array[$i] < $secmin) { $thirdmin = $secmin; $secmin = $array[$i]; } /* Check if current element is less than then update third */ else if ($array[$i] < $thirdmin) $thirdmin = $array[$i]; } echo "First min = ".$firstmin."\n"; echo "Second min = ".$secmin."\n"; echo "Third min = ".$thirdmin."\n"; } // Driver code $array= array(4, 9, 1, 32, 12); $n = sizeof($array) / sizeof($array[0]); Print3Smallest($array, $n); // This code is contributed by mits ?> |
Output:
First min = 1 Second min = 4 Third min = 9
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