Sorting array using Stacks
Given an array of elements, the task is to sort these elements using a stack.
Prerequisites: Stacks
Examples:
Input : 8 5 7 1 9 12 10 Output : 1 5 7 8 9 10 12 Explanation : Output is sorted element set Input : 7 4 10 20 2 5 9 1 Output : 1 2 4 5 7 9 10 20
We basically use Sort a stack using a temporary stack. Then we put sorted stack elements back to the array.
Implementation:
C++
// C++ program to sort an array using stack #include <bits/stdc++.h> using namespace std; // This function return the sorted stack stack< int > sortStack(stack< int > input) { stack< int > tmpStack; while (!input.empty()) { // pop out the first element int tmp = input.top(); input.pop(); // while temporary stack is not empty // and top of stack is smaller than temp while (!tmpStack.empty() && tmpStack.top() < tmp) { // pop from temporary stack and // push it to the input stack input.push(tmpStack.top()); tmpStack.pop(); } // push temp in temporary of stack tmpStack.push(tmp); } return tmpStack; } void sortArrayUsingStacks( int arr[], int n) { // Push array elements to stack stack< int > input; for ( int i=0; i<n; i++) input.push(arr[i]); // Sort the temporary stack stack< int > tmpStack = sortStack(input); // Put stack elements in arrp[] for ( int i=0; i<n; i++) { arr[i] = tmpStack.top(); tmpStack.pop(); } } // main function int main() { int arr[] = {10, 5, 15, 45}; int n = sizeof (arr)/ sizeof (arr[0]); sortArrayUsingStacks(arr, n); for ( int i=0; i<n; i++) cout << arr[i] << " " ; return 0; } |
Java
// Java program to sort an // array using stack import java.io.*; import java.util.*; class GFG { // This function return // the sorted stack static Stack<Integer> sortStack(Stack<Integer> input) { Stack<Integer> tmpStack = new Stack<Integer>(); while (!input.empty()) { // pop out the // first element int tmp = input.peek(); input.pop(); // while temporary stack is // not empty and top of stack // is smaller than temp while (!tmpStack.empty() && tmpStack.peek() < tmp) { // pop from temporary // stack and push it // to the input stack input.push(tmpStack.peek()); tmpStack.pop(); } // push temp in // temporary of stack tmpStack.push(tmp); } return tmpStack; } static void sortArrayUsingStacks( int []arr, int n) { // push array elements // to stack Stack<Integer> input = new Stack<Integer>(); for ( int i = 0 ; i < n; i++) input.push(arr[i]); // Sort the temporary stack Stack<Integer> tmpStack = sortStack(input); // Put stack elements // in arrp[] for ( int i = 0 ; i < n; i++) { arr[i] = tmpStack.peek(); tmpStack.pop(); } } // Driver Code public static void main(String args[]) { int []arr = { 10 , 5 , 15 , 45 }; int n = arr.length; sortArrayUsingStacks(arr, n); for ( int i = 0 ; i < n; i++) System.out.print(arr[i] + " " ); } } // This code is contributed by // Manish Shaw(manishshaw1) |
Python3
# Python3 program to sort an array using stack # This function return the sorted stack def sortStack( input ): tmpStack = [] while ( len ( input ) > 0 ): # pop out the first element tmp = input [ - 1 ] input .pop() # while temporary stack is not empty # and top of stack is smaller than temp while ( len (tmpStack) > 0 and tmpStack[ - 1 ] < tmp): # pop from temporary stack and # append it to the input stack input .append(tmpStack[ - 1 ]) tmpStack.pop() # append temp in temporary of stack tmpStack.append(tmp) return tmpStack def sortArrayUsingStacks(arr, n): # append array elements to stack input = [] i = 0 while ( i < n ): input .append(arr[i]) i = i + 1 # Sort the temporary stack tmpStack = sortStack( input ) i = 0 # Put stack elements in arrp[] while (i < n): arr[i] = tmpStack[ - 1 ] tmpStack.pop() i = i + 1 return arr # Driver code arr = [ 10 , 5 , 15 , 45 ] n = len (arr) arr = sortArrayUsingStacks(arr, n) i = 0 while (i < n): print (arr[i] ,end = " " ) i = i + 1 # This code is contributed by Arnab Kundu |
C#
// C# program to sort an // array using stack using System; using System.Collections.Generic; class GFG { // This function return // the sorted stack static Stack< int > sortStack(Stack< int > input) { Stack< int > tmpStack = new Stack< int >(); while (input.Count != 0) { // pop out the // first element int tmp = input.Peek(); input.Pop(); // while temporary stack is // not empty and top of stack // is smaller than temp while (tmpStack.Count != 0 && tmpStack.Peek() < tmp) { // pop from temporary // stack and push it // to the input stack input.Push(tmpStack.Peek()); tmpStack.Pop(); } // push temp in // temporary of stack tmpStack.Push(tmp); } return tmpStack; } static void sortArrayUsingStacks( int []arr, int n) { // Push array elements // to stack Stack< int > input = new Stack< int >(); for ( int i = 0; i<n; i++) input.Push(arr[i]); // Sort the temporary stack Stack< int > tmpStack = sortStack(input); // Put stack elements in arrp[] for ( int i = 0; i < n; i++) { arr[i] = tmpStack.Peek(); tmpStack.Pop(); } } // Driver Code static void Main() { int []arr = new int [] {10, 5, 15, 45}; int n = arr.Length; sortArrayUsingStacks(arr, n); for ( int i = 0; i < n; i++) Console.Write(arr[i] + " " ); } } // This code is contributed by // Manish Shaw(manishshaw1) |
Javascript
<script> // Javascript program to sort an array using stack // This function return the sorted stack function sortStack(input) { var tmpStack = []; while (input.length!=0) { // pop out the first element var tmp = input[input.length-1]; input.pop(); // while temporary stack is not empty // and top of stack is smaller than temp while (tmpStack.length!=0 && tmpStack[tmpStack.length-1] < tmp) { // pop from temporary stack and // push it to the input stack input.push(tmpStack[tmpStack.length-1]); tmpStack.pop(); } // push temp in temporary of stack tmpStack.push(tmp); } return tmpStack; } function sortArrayUsingStacks(arr, n) { // Push array elements to stack var input = []; for ( var i=0; i<n; i++) input.push(arr[i]); // Sort the temporary stack var tmpStack = sortStack(input); // Put stack elements in arrp[] for ( var i=0; i<n; i++) { arr[i] = tmpStack[tmpStack.length-1]; tmpStack.pop(); } } // main function var arr = [10, 5, 15, 45]; var n = arr.length; sortArrayUsingStacks(arr, n); for ( var i=0; i<n; i++) document.write( arr[i] + " " ); </script> |
Output
5 10 15 45
Complexity Analysis:
- Time Complexity: O(n*n).
- Auxiliary Space: O(n) since auxiliary array is being used to create stack.
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