The Stooge sort is a recursive sorting algorithm. It is defined as below (for ascending order sorting).
Step 1 : If value at index 0 is greater than
value at last index, swap them.
Step 2: Recursively,
a) Stooge sort the initial 2/3rd of the array.
b) Stooge sort the last 2/3rd of the array.
c) Stooge sort the initial 2/3rd again to confirm.
NOTE: Always take the ceil of ((2/3)*N) for selecting elements.
Illustration:
Input : 2 4 5 3 1
Output : 1 2 3 4 5
Explanation:
Initially, swap 2 and 1 following above step 1.
1 4 5 3 2
Now, recursively sort initial 2/3rd of the elements.
1 4 5 3 2
1 3 4 5 2
Then, recursively sort last 2/3rd of the elements.
1 3 4 5 2
1 2 3 4 5
Again, sort the initial 2/3rd of the elements to confirm final data is sorted.
1 2 3 4 5
C++
// C++ code to implement stooge sort #include <iostream> using namespace std; // Function to implement stooge sort void stoogesort(int arr[], int l, int h) { if (l >= h) return; // If first element is smaller than last, // swap them if (arr[l] > arr[h]) swap(arr[l], arr[h]); // If there are more than 2 elements in // the array if (h - l + 1 > 2) { int t = (h - l + 1) / 3; // Recursively sort first 2/3 elements stoogesort(arr, l, h - t); // Recursively sort last 2/3 elements stoogesort(arr, l + t, h); // Recursively sort first 2/3 elements // again to confirm stoogesort(arr, l, h - t); } } // Driver Code int main() { int arr[] = { 2, 4, 5, 3, 1 }; int n = sizeof(arr) / sizeof(arr[0]); // Calling Stooge Sort function to sort // the array stoogesort(arr, 0, n - 1); // Display the sorted array for (int i = 0; i < n; i++) cout << arr[i] << " "; return 0; } |
Java
// Java program to implement stooge sort import java.io.*; public class stooge { // Function to implement stooge sort static void stoogesort(int arr[], int l, int h) { if (l >= h) return; // If first element is smaller // than last, swap them if (arr[l] > arr[h]) { int t = arr[l]; arr[l] = arr[h]; arr[h] = t; } // If there are more than 2 elements in // the array if (h - l + 1 > 2) { int t = (h - l + 1) / 3; // Recursively sort first 2/3 elements stoogesort(arr, l, h - t); // Recursively sort last 2/3 elements stoogesort(arr, l + t, h); // Recursively sort first 2/3 elements // again to confirm stoogesort(arr, l, h - t); } } // Driver Code public static void main(String args[]) { int arr[] = { 2, 4, 5, 3, 1 }; int n = arr.length; stoogesort(arr, 0, n - 1); for (int i = 0; i < n; i++) System.out.print(arr[i] + " "); } } // Code Contributed by Mohit Gupta_OMG <(0_o)> |
Python3
# Python program to implement stooge sort def stoogesort(arr, l, h): if l >= h: return # If first element is smaller # than last, swap them if arr[l]>arr[h]: t = arr[l] arr[l] = arr[h] arr[h] = t # If there are more than 2 elements in # the array if h-l + 1 > 2: t = (int)((h-l + 1)/3) # Recursively sort first 2 / 3 elements stoogesort(arr, l, (h-t)) # Recursively sort last 2 / 3 elements stoogesort(arr, l + t, (h)) # Recursively sort first 2 / 3 elements # again to confirm stoogesort(arr, l, (h-t)) # deriver arr = [2, 4, 5, 3, 1] n = len(arr) stoogesort(arr, 0, n-1) for i in range(0, n): print(arr[i], end = ' ') # Code Contributed by Mohit Gupta_OMG <(0_o)> |
C#
// C# program to implement stooge sort using System; class GFG { // Function to implement stooge sort static void stoogesort(int[] arr, int l, int h) { if (l >= h) return; // If first element is smaller // than last, swap them if (arr[l] > arr[h]) { int t = arr[l]; arr[l] = arr[h]; arr[h] = t; } // If there are more than 2 // elements in the array if (h - l + 1 > 2) { int t = (h - l + 1) / 3; // Recursively sort first // 2/3 elements stoogesort(arr, l, h - t); // Recursively sort last // 2/3 elements stoogesort(arr, l + t, h); // Recursively sort first // 2/3 elements again to // confirm stoogesort(arr, l, h - t); } } // Driver Code public static void Main() { int[] arr = { 2, 4, 5, 3, 1 }; int n = arr.Length; // Calling Stooge Sort function // to sort the array stoogesort(arr, 0, n - 1); // Display the sorted array for (int i = 0; i < n; i++) Console.Write(arr[i] + " "); } } // This code is contributed by Sam007. |
Output:
1 2 3 4 5
The running time complexity of stooge sort can be written as,
T(n) = 3T(3n/2) + ?(1)
Solution of above recurrence is O(n(log3/log1.5)) = O(n2.709), hence it is slower than even bubble sort(n^2).
Reference:
Wikipedia
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