Middle of three using minimum comparisons

Difficulty Level : Easy
Last Updated : 23 May, 2018

Given three distinct numbers a, b and c find the number with a value in middle.

Examples :

Input : a = 20, b = 30, c = 40
Output : 30

Input : a = 12, n = 32, c = 11
Output : 12

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

Simple Approach :

C++

// CPP program to find  middle of three distinct  
// numbers 
#include <bits/stdc++.h> 
using namespace std; 
  
int middleOfThree(int a, int b, int c) 
{ 
    // Checking for b 
    if ((a < b && b < c) || (c < b && b < a)) 
       return b; 
  
    // Checking for a 
    else if ((b < a && a < c) || (c < a && a < b)) 
       return a; 
  
    else
       return c; 
} 
  
// Driver Code 
int main() 
{ 
    int a = 20, b = 30, c = 40; 
    cout << middleOfThree(a, b, c); 
    return 0; 
} 

Java

// Java program to find middle of  
// three distinct numbers 
import java.util.*; 
  
class Middle 
{    
    // Function to find the middle of three number 
    public static int middleOfThree(int a, int b, 
                                          int c) 
    { 
        // Checking for b 
        if ((a < b && b < c) || (c < b && b < a)) 
            return b; 
  
        // Checking for a 
        else if ((b < a && a < c) || (c < a && a < b)) 
        return a; 
  
        else
        return c; 
    } 
      
    // driver code 
    public static void main(String[] args) 
    { 
        int a = 20, b = 30, c = 40; 
        System.out.println( middleOfThree(a, b, c) ); 
    } 
} 
  
// This code is contributed by rishabh_jain 

Python3

# Python3 program to find middle  
# of three distinct numbers 
  
def middleOfThree(a, b, c): 
      
    # Checking for b 
    if ((a < b and b < c) or (c < b and b < a)) : 
        return b; 
  
    # Checking for a 
    if ((b < a and a < c) or (c < a and a < b)) : 
        return a; 
  
    else : 
        return c 
  
# Driver Code 
a = 20
b = 30
c = 40
print(middleOfThree(a, b, c)) 
  
# This code is contributed by rishabh_jain 

C#

// C# program to find middle of  
// three distinct numbers 
using System; 
  
class Middle 
{  
    // Function to find the middle of three number 
    public static int middleOfThree(int a, int b, 
                                        int c) 
    { 
        // Checking for b 
        if ((a < b && b < c) || (c < b && b < a)) 
            return b; 
  
        // Checking for a 
        else if ((b < a && a < c) || (c < a && a < b)) 
        return a; 
  
        else
        return c; 
    } 
      
    // Driver code 
    public static void Main() 
    { 
        int a = 20, b = 30, c = 40; 
        Console.WriteLine( middleOfThree(a, b, c) ); 
    } 
} 
  
// This code is contributed by vt_m 

PHP

<?php 
// PHP program to find middle 
// of three distinct numbers  
  
function middleOfThree($a, $b, $c) 
{ 
      
    // Checking for b 
    if (($a < $b && $b < $c) or 
        ($c < $b && $b < $a)) 
    return $b; 
  
    // Checking for a 
    else if (($b < $a and $a < $c) or
             ($c < $a and $a < $b)) 
    return $a; 
  
    else
    return $c; 
} 
  
    // Driver Code 
    $a = 20;  
    $b = 30; 
    $c = 40; 
    echo middleOfThree($a, $b, $c); 
      
// This code is contributed by anuj_67. 
?> 

Output :

But approach used above is not efficient because of extra comparisons, which can be easily minimized. In case first part is false, it will execute remaining half to check the condition. This problem remains same if we are checking for a also.

Better Approach (Needs less comparison):

C++

// CPP program to find middle of three distinct 
// numbers 
#include <bits/stdc++.h> 
using namespace std; 
  
// Function to find the middle of three numbers 
int middleOfThree(int a, int b, int c) 
{ 
    // Compare each three number to find middle  
    // number. Enter only if a > b 
    if (a > b)  
    { 
        if (b > c) 
            return b; 
        else if (a > c) 
            return c; 
        else
            return a; 
    } 
    else 
    { 
        // Decided a is not greater than b. 
        if (a > c) 
            return a; 
        else if (b > c) 
            return c; 
        else
            return b; 
    } 
} 
  
// Driver Code 
int main() 
{ 
    int a = 20, b = 30, c = 40; 
    cout << middleOfThree(a, b, c); 
    return 0; 
} 

Java

// Java program to find middle of  
// three distinct numbers 
import java.util.*; 
  
class Middle 
{    
    // Function to find the middle of three number 
    public static int middleOfThree(int a, int b,  
                                          int c) 
    { 
        // Compare each three number to find  
        // middle number. Enter only if a > b 
        if (a > b)  
        { 
            if (b > c) 
                return b; 
            else if (a > c) 
                return c; 
            else
                return a; 
        } 
        else
        { 
            // Decided a is not greater than b. 
            if (a > c) 
                return a; 
            else if (b > c) 
                return c; 
            else
                return b; 
        } 
    } 
      
    // driver code 
    public static void main(String[] args) 
    { 
        int a = 20, b = 30, c = 40; 
        System.out.println(middleOfThree(a, b, c)); 
    } 
} 
  
// This code is contributed by rishabh_jain 

Python3

# Python3 program to find middle  
# of three distinct numbers 
  
# Function to find the middle of three numbers 
def middleOfThree(a, b, c) : 
      
    # Compare each three number to find  
    # middle number. Enter only if a > b 
    if a > b :  
        if (b > c): 
            return b 
        elif (a > c) : 
            return c 
        else : 
            return a  
    else: 
        # Decided a is not greater than b. 
        if (a > c) : 
            return a 
        elif (b > c) : 
            return c 
        else : 
            return b 
  
# Driver Code 
a = 20
b = 30
c = 40
print( middleOfThree(a, b, c) ) 
  
# This code is contributed by rishabh_jain 

C#

// C# program to find middle of  
// three distinct numbers 
using System; 
  
class Middle 
{  
    // Function to find the middle of three number 
    public static int middleOfThree(int a, int b,  
                                            int c) 
    { 
        // Compare each three number to find  
        // middle number. Enter only if a > b 
        if (a > b)  
        { 
            if (b > c) 
                return b; 
            else if (a > c) 
                return c; 
            else
                return a; 
        } 
        else
        { 
            // Decided a is not greater than b. 
            if (a > c) 
                return a; 
            else if (b > c) 
                return c; 
            else
                return b; 
        } 
    } 
      
    // Driver code 
    public static void Main() 
    { 
        int a = 20, b = 30, c = 40; 
        Console.WriteLine(middleOfThree(a, b, c)); 
    } 
} 
  
// This code is contributed by vt_m 

PHP

<?php 
// PHP program to find middle 
// of three distinct numbers 
  
// Function to find the middle 
// of three numbers 
function middleOfThree( $a, $b, $c) 
{ 
      
    // Compare each three number 
    // to find middle number.  
    // Enter only if a > b 
    if ($a > $b)  
    { 
        if ($b > $c) 
            return $b; 
        else if ($a > $c) 
            return $c; 
        else
            return $a; 
    } 
    else
    { 
          
        // Decided a is not  
        // greater than b. 
        if ($a > $c) 
            return $a; 
        else if ($b > $c) 
            return $c; 
        else
            return $b; 
    } 
} 
  
    // Driver Code 
    $a = 20; $b = 30; 
    $c = 40; 
    echo middleOfThree($a, $b, $c); 
  
// This code is contributed by anuj_67. 
?> 

Output:

This approach is efficient and having less number of comparisons. Outer IF loop will only be executed if a > b otherwise, outer ELSE will be executed.
Other Efficient Approach :

C++

// CPP program to find middle of three distinct  
// numbers 
#include <bits/stdc++.h> 
using namespace std; 
  
// Function to find the middle of three number 
int middleOfThree(int a, int b, int c) 
{ 
    // x is positive if a is greater than b.  
    // x is negative if b is greater than a. 
    int x = a - b; 
  
    int y = b - c;  // Similar to x 
    int z = a - c;  // Similar to x and y. 
  
    // Checking if b is middle (x and y both 
    // are positive) 
    if (x * y > 0) 
        return b; 
  
    // Checking if c is middle (x and z both 
    // are positive) 
    else if (x * z > 0) 
        return c; 
    else
        return a; 
} 
  
// Driver Code 
int main() 
{ 
    int a = 20, b = 30, c = 40; 
    cout << middleOfThree(a, b, c); 
    return 0; 
} 

Java

//java program to find middle of three distinct  
// numbers 
import java.util.*; 
  
class Middle 
{    
    // Function to find the middle of three number 
    public static int middleOfThree(int a, int b,  
                                          int c) 
    { 
        // x is positive if a is greater than b.  
        // x is negative if b is greater than a. 
        int x = a - b; 
  
        int y = b - c; // Similar to x 
        int z = a - c; // Similar to x and y. 
  
        // Checking if b is middle (x and y  
        // both are positive) 
        if (x * y > 0) 
            return b; 
  
        // Checking if c is middle (x and z  
        // both are positive) 
        else if (x * z > 0) 
            return c; 
        else
            return a; 
    } 
      
    // driver code 
    public static void main(String[] args) 
    { 
        int a = 20, b = 30, c = 40; 
        System.out.println( middleOfThree(a, b, c) ); 
    } 
} 
  
// This code is contributed by rishabh_jain 

Python3

# Python3 program to find middle  
# of three distinct numbers 
  
# Function to find the middle of three number 
def middleOfThree(a, b, c) : 
      
    # x is positive if a is greater than b.  
    # x is negative if b is greater than a. 
    x = a - b 
  
    # Similar to x 
    y = b - c 
      
    # Similar to x and y. 
    z = a - c  
  
    # Checking if b is middle (x and y  
    # both are positive) 
    if x * y > 0: 
        return b 
  
    # Checking if c is middle (x and z  
    # both are positive) 
    elif (x * z > 0) : 
        return
    else : 
        return a 
  
# Driver Code 
a = 20
b = 30
c = 40
print(middleOfThree(a, b, c)) 
  
# This code is contributed by rishabh_jain 

C#

//C# program to find middle of three distinct  
// numbers 
using System; 
  
class Middle 
{  
    // Function to find the middle of three number 
    public static int middleOfThree(int a, int b,  
                                        int c) 
    { 
        // x is positive if a is greater than b.  
        // x is negative if b is greater than a. 
        int x = a - b; 
          
        // Similar to x 
        int y = b - c;  
          
         // Similar to x and y. 
        int z = a - c; 
  
        // Checking if b is middle (x and y  
        // both are positive) 
        if (x * y > 0) 
            return b; 
  
        // Checking if c is middle (x and z  
        // both are positive) 
        else if (x * z > 0) 
            return c; 
        else
            return a; 
    } 
      
    // Driver code 
    public static void Main() 
    { 
        int a = 20, b = 30, c = 40; 
        Console.WriteLine( middleOfThree(a, b, c) ); 
    } 
} 
  
// This code is contributed by vt_m 

PHP

<?php 
// PHP program to find middle  
// of three distinct numbers 
  
// Function to find the 
// middle of three number 
function middleOfThree($a, $b, $c) 
{ 
      
    // x is positive if a 
    // is greater than b.  
    // x is negative if b  
    // is greater than a. 
    $x = $a - $b; 
  
    // Similar to x 
    $y = $b - $c;  
      
    // Similar to x and y. 
    $z = $a - $c;  
  
    // Checking if b is 
    // middle (x and y both 
    // are positive) 
    if ($x * $y > 0) 
        return $b; 
  
    // Checking if c is  
    // middle (x and z both 
    // are positive) 
    else if ($x * $z > 0) 
        return $c; 
    else
        return $a; 
} 
  
    // Driver Code 
    $a = 20; 
    $b = 30;  
    $c = 40; 
    echo middleOfThree($a, $b, $c); 
  
// This code is contributed by anuj_67. 
?> 

Output :

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Related Articles

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

C++

Java

Python3

C#

PHP

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Java

Python3

C#

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C++

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Python3

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PHP