Count Number of animals in a zoo from given number of head and legs - GeeksforGeeks

14 Apr, 2021
Given the total number of Legs and Head of Rabbits and Pigeons. The task is to calculate the number of Rabbits and Pigeons.Examples:  
Input: Heads = 200, Legs = 540 
Output: Rabbits = 70, Pigeons = 130

Input: Heads = 100, Legs = 300
Output: Rabbits = 50, Pigeons = 50
 
 
Let the total no. of Heads = 200 and Legs = 540. Let the number of Head and Legs of Rabbits = X and that of Pigeons = Y. so, X + Y = 200 ..equation 1 (no. of the heads of a rabbit and a pigeon = total no. of heads) (As both of them has 1 head) 4X + 2Y = 540 ...equation 2 (no. of the legs of the rabbit and a pigeon = total no. of legs) (Rabbit have 4 legs and pigeons have 2 legs) Now, solving equation 1 and 2 we get, 4X = 540 – 2Y 4X = 540 – 2 * (200 – X) 4X = 540 – 400 + 2X 2X = 140 => X = 70X = 70 and Y = 130. hence, Rabbits = 70 and Pigeons = 130  
Below is the implementation of the above approach:  
C++
Java
Python3
C#
PHP
Javascript
// C++ implementation of above approach#include <bits/stdc++.h>using namespace std; // Function that calculates Rabbitsint countRabbits(int Heads, int Legs){    int count = 0;     count = (Legs)-2 * (Heads);    count = count / 2;     return count;} // Driver codeint main(){    int Heads = 100, Legs = 300;     int Rabbits = countRabbits(Heads, Legs);     cout << "Rabbits = " << Rabbits << endl;    cout << "Pigeons = " << Heads - Rabbits << endl;     return 0;}
// Java implementation of above approachimport java.util.*;import java.lang.*; class GFG{// Function that calculates Rabbitsstatic int countRabbits(int Heads,                        int Legs){    int count = 0;     count = (Legs) - 2 * (Heads);    count = count / 2;     return count;} // Driver codepublic static void main(String args[]){    int Heads = 100, Legs = 300;     int Rabbits = countRabbits(Heads, Legs);     System.out.println("Rabbits = " +                        Rabbits);    System.out.println("Pigeons = " +                      (Heads - Rabbits));}} // This code is contributed// by Akanksha Rai(Abby_akku)
# Python 3 implementation of above approach # Function that calculates Rabbitsdef countRabbits(Heads, Legs):    count = 0     count = (Legs) - 2 * (Heads)    count = count / 2     return count # Driver codeif __name__ == '__main__':    Heads = 100    Legs = 300     Rabbits = countRabbits(Heads, Legs)     print("Rabbits =", Rabbits)    print("Pigeons =", Heads - Rabbits) # This code is contributed# by Surendra_Gangwar
// C# implementation of above approachusing System; class GFG{// Function that calculates Rabbitsstatic int countRabbits(int Heads,                        int Legs){    int count = 0;     count = (Legs) - 2 * (Heads);    count = count / 2;     return count;} // Driver codepublic static void Main(){    int Heads = 100, Legs = 300;     int Rabbits = countRabbits(Heads, Legs);     Console.WriteLine("Rabbits = " +                       Rabbits);    Console.WriteLine("Pigeons = " +                     (Heads - Rabbits));}} // This code is contributed// by Akanksha Rai(Abby_akku)
<?php// PHP implementation of above approach // Function that calculates Rabbitsfunction countRabbits($Heads, $Legs){    $count = 0;     $count = ($Legs) - 2 * ($Heads);    $count = (int) $count / 2;     return $count;} // Driver code$Heads = 100;$Legs = 300;$Rabbits = countRabbits($Heads, $Legs); echo "Rabbits = " , $Rabbits , "\n";echo "Pigeons = " , $Heads -                    $Rabbits, "\n"; // This code is contributed// by Sach_Code?>
<script> // Javascript implementation of above approach // Function that calculates Rabbitsfunction countRabbits(Heads, Legs){    var count = 0;     count = (Legs)-2 * (Heads);    count = count / 2;     return count;} // Driver codevar Heads = 100, Legs = 300;var Rabbits = countRabbits(Heads, Legs);document.write( "Rabbits = " + Rabbits + "<br>");document.write( "Pigeons = " + (Heads - Rabbits)); </script>
Rabbits = 50
Pigeons = 50
 
SURENDRA_GANGWAR
Akanksha_Rai
Sach_Code
noob2000
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