Check if minimum element in array is less than or equals half of every other element

Given an array arr[], the task is to check if the minimum element in the array is less than or equal to half of every other element. If it is then print “yes” otherwise print “no”.

Note: The minimum number in the given array is always unique.

Examples:

Input: arr = {2, 1, 4, 5}
Output: Yes
Explanation:
1 is the minimum element in the array arr[] and on dividing 2, 4, 5 by 2 we get 1, 2, 2.5 which is greater than or equal to the minimum number. Hence, print “yes”.

Input : arr = {2, 4, 5, 3}
Output : No
Explanation:
2 is the minimum element in the array arr[] and on dividing 4, 5, 3 by 2 we get 2, 2.5, 1.5 in which the integer 3 does not return a value which is greater than or equal to the minimum number ( 1.5 < 2). Hence, print "no".



Method 1:

To solve the problem mentioned above we have to find the smallest element with the help of loops and then scan through the entire array again and check if twice the smallest element is smaller than or equal to every other element. But this solution takes O(N) time using two loops and can be optimized further where only one iteration is involved.

Method 2:

To optimize the above solution we can find the smallest as well as the second smallest element in a single iteration itself. Then simply check if twice of the smallest element is smaller than or equal to the second smallest element.

Below is the implementation of the above approach:

C++

filter_none

edit
close

play_arrow

link
brightness_4
code

// C++ implementation to Check if the minimum element in the
// array is greater than or equal to half of every other elements
#include <bits/stdc++.h>
using namespace std;
  
// Function to Check if the minimum element in the array is
// greater than or equal to half of every other element
void checkMin(int arr[], int len)
{
  
    // Initialise the variables to store
    // smallest and second smallest
    int smallest = INT_MAX, secondSmallest = INT_MAX;
  
    for (int i = 0; i < len; i++) {
  
        // Check if current element is smaller than smallest,
        // the current smallest will become secondSmallest
        // and current element will be the new smallest
        if (arr[i] < smallest) {
            secondSmallest = smallest;
            smallest = arr[i];
        }
  
        // Check if current element is smaller than
        // secondSmallest simply update the latter
        else if (arr[i] < secondSmallest) {
            secondSmallest = arr[i];
        }
    }
  
    if (2 * smallest <= secondSmallest)
        cout << "Yes";
    else
        cout << "No";
}
  
// Driver code
int main()
{
    int arr[] = { 2, 3, 4, 5 };
  
    int len = sizeof(arr) / sizeof(arr[0]);
  
    checkMin(arr, len);
}

chevron_right


Java

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java implementation to check 
// if the minimum element in the
// array is greater than or equal
// to half of every other elements
import java.util.*;
class GFG{
  
// Function to Check if the minimum
// element in the array is greater
// than or equal to half of every
// other elements
static void checkMin(int arr[], int len)
{
      
    // Initialise the variables to store
    // smallest and second smallest
    int smallest = Integer.MAX_VALUE; 
    int secondSmallest = Integer.MAX_VALUE;
  
    for(int i = 0; i < len; i++)
    {
         
       // Check if current element is smaller than  
       // smallest, the current smallest will  
       // become secondSmallest and current  
       // element will be the new smallest
       if (arr[i] < smallest)
       {
           secondSmallest = smallest;
           smallest = arr[i];
       }
         
       // Check if current element is smaller than
       // secondSmallest simply update the latter
       else if (arr[i] < secondSmallest)
       {
           secondSmallest = arr[i];
       }
    }
    if (2 * smallest <= secondSmallest)
        System.out.print("Yes");
    else
        System.out.print("No");
}
  
// Driver code
public static void main(String[] args)
{
    int arr[] = { 2, 3, 4, 5 };
    int len = arr.length;
  
    checkMin(arr, len);
}
}
  
// This code is contributed by amal kumar choubey

chevron_right


Python3

filter_none

edit
close

play_arrow

link
brightness_4
code

# Python3 implementation to Check if 
# the minimum element in the array
# is greater than or equal to half 
# of every other element
import math
  
# Function to Check if the minimum element 
# in the array is greater than or equal to 
# half of every other element
def checkMin(arr, n):
  
    # Initialise the variables to store
    # smallest and second smallest
    smallest = math.inf
    secondSmallest = math.inf
  
    for i in range(n):
          
        # Check if current element is 
        # smaller than smallest, 
        # the current smallest will become 
        # secondSmallest and current element 
        # will be the new smallest
        if(arr[i] < smallest):
            secondSmallest = smallest
            smallest = arr[i]
              
        # Check if current element is smaller than
        # secondSmallest simply update the latter
        elif(arr[i] < secondSmallest):
            secondSmallest = arr[i]
  
    if(2 * smallest <= secondSmallest):
        print("Yes")
    else:
        print("No")
  
# Driver code 
if __name__ == '__main__':
    arr = [ 2, 3, 4, 5 ]
  
    n = len(arr)
  
    checkMin(arr, n)
      
# This code is contributed by Shivam Singh.

chevron_right


C#

filter_none

edit
close

play_arrow

link
brightness_4
code

// C# implementation to check 
// if the minimum element in the
// array is greater than or equal
// to half of every other elements
using System;
  
class GFG{
  
// Function to Check if the minimum
// element in the array is greater
// than or equal to half of every
// other elements
static void checkMin(int []arr, int len)
{
      
    // Initialise the variables to store
    // smallest and second smallest
    int smallest = int.MaxValue; 
    int secondSmallest = int.MaxValue;
  
    for(int i = 0; i < len; i++)
    {
         
       // Check if current element is smaller than 
       // smallest, the current smallest will 
       // become secondSmallest and current 
       // element will be the new smallest
       if (arr[i] < smallest)
       {
           secondSmallest = smallest;
           smallest = arr[i];
       }
         
       // Check if current element is smaller than
       // secondSmallest simply update the latter
       else if (arr[i] < secondSmallest)
       {
           secondSmallest = arr[i];
       }
    }
    if (2 * smallest <= secondSmallest)
        Console.Write("Yes");
    else
        Console.Write("No");
}
  
// Driver code
public static void Main(String[] args)
{
    int []arr = { 2, 3, 4, 5 };
    int len = arr.Length;
  
    checkMin(arr, len);
}
}
  
// This code is contributed by amal kumar choubey

chevron_right


Output:

No

Time Complexity: O(n)

competitive-programming-img




My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.