# Minimum integer that can be obtained by swapping adjacent digits of different parity

• Difficulty Level : Medium
• Last Updated : 26 Nov, 2021

Given an integer N, the task is to find the minimum integer that can be obtained from the given integer such that the adjacent digits of different parity can be swapped any no of times.
Two digits of different parity means that they will have different remainders when divided by two.
Examples:

Input: N = 64432
Output: 36442
Explanation:
Swap the 4th and 3rd digit; N = 64342
Swap the 3rd and 2nd digit; N = 63442
Swap the 2nd and 1st digit; N = 36442
Input :
3137
Output :
3137

Approach: The idea of the approach is to use two stacks to keep the digits of the number.

• In one stack, numbers which are divisible by two can be stored.
• In another stack, numbers which are not divisible by two can be stored.
• The elements are then pushed into both the stacks from reverse order of the number.
• Now, the element from the stack whose top contains the smaller element is popped and concatenated with the answer till one of the stacks is empty.
• The remaining elements of the stack are then concatenated which is not empty with the answer and finally the output is returned.

Below is the implementation of the above approach.

## CPP

 `// C++ implementation of the above approach.``#include ``using` `namespace` `std;``// Function to return the minimum number``int` `minimumNo(``int` `n)``{``    ``int` `ans = 0;``    ``stack<``int``> stack1;``    ``stack<``int``> stack2;``    ``while` `(n != 0) {``        ``int` `r = n % 10;` `        ``// Store the elements which are``        ``// divisible by two in stack1``        ``if` `(r % 2 == 0) {``            ``stack1.push(r);``        ``}` `        ``// Store the elements which are``        ``// not divisible by two in stack2.``        ``else` `{``            ``stack2.push(r);``        ``}``        ``n = n / 10;``    ``}` `    ``while` `(!stack1.empty() && !stack2.empty()) {` `        ``// Concatenate the answer with smaller value``        ``// of the topmost elements of both the``        ``// stacks and then pop that element``        ``if` `(stack1.top() < stack2.top()) {``            ``ans = ans * 10 + stack1.top();``            ``stack1.pop();``        ``}``        ``else` `{``            ``ans = ans * 10 + stack2.top();``            ``stack2.pop();``        ``}``    ``}` `    ``// Concatenate the answer with remaining``    ``// values of stack1.``    ``while` `(!stack1.empty()) {``        ``ans = ans * 10 + stack1.top();``        ``stack1.pop();``    ``}` `    ``// Concatenate the answer with remaining``    ``// values of stack2.``    ``while` `(!stack2.empty()) {``        ``ans = ans * 10 + stack2.top();``        ``stack2.pop();``    ``}``    ``return` `ans;``}` `// Driver code``int` `main()``{``    ``int` `n1 = 64432;` `    ``// Function calling``    ``cout << minimumNo(n1) << endl;` `    ``int` `n2 = 3137;``    ``cout << minimumNo(n2) << endl;` `    ``return` `0;``}`

## Java

 `// Java implementation of the above approach.``import` `java.util.*;` `class` `GFG``{``    ` `// Function to return the minimum number``static` `int` `minimumNo(``int` `n)``{``    ``int` `ans = ``0``;``    ``Stack stack1 = ``new` `Stack();``    ``Stack stack2 = ``new` `Stack();``    ``while` `(n != ``0``)``    ``{``        ``int` `r = n % ``10``;` `        ``// Store the elements which are``        ``// divisible by two in stack1``        ``if` `(r % ``2` `== ``0``)``        ``{``            ``stack1.add(r);``        ``}` `        ``// Store the elements which are``        ``// not divisible by two in stack2.``        ``else``        ``{``            ``stack2.add(r);``        ``}``        ``n = n / ``10``;``    ``}` `    ``while` `(!stack1.isEmpty() && !stack2.isEmpty())``    ``{` `        ``// Concatenate the answer with smaller value``        ``// of the topmost elements of both the``        ``// stacks and then pop that element``        ``if` `(stack1.peek() < stack2.peek())``        ``{``            ``ans = ans * ``10` `+ stack1.peek();``            ``stack1.pop();``        ``}``        ``else``        ``{``            ``ans = ans * ``10` `+ stack2.peek();``            ``stack2.pop();``        ``}``    ``}` `    ``// Concatenate the answer with remaining``    ``// values of stack1.``    ``while` `(!stack1.isEmpty())``    ``{``        ``ans = ans * ``10` `+ stack1.peek();``        ``stack1.pop();``    ``}` `    ``// Concatenate the answer with remaining``    ``// values of stack2.``    ``while` `(!stack2.isEmpty())``    ``{``        ``ans = ans * ``10` `+ stack2.peek();``        ``stack2.pop();``    ``}``    ``return` `ans;``}` `// Driver code``public` `static` `void` `main(String[] args)``{``    ``int` `n1 = ``64432``;` `    ``// Function calling``    ``System.out.print(minimumNo(n1) + ``"\n"``);` `    ``int` `n2 = ``3137``;``    ``System.out.print(minimumNo(n2) + ``"\n"``);``}``}` `// This code is contributed by 29AjayKumar`

## Python3

 `# Python3 implementation of the above approach.` `# Function to return the minimum number``def` `minimumNo(n):``    ``ans ``=` `0``    ``stack1 ``=` `[]``    ``stack2 ``=` `[]``    ``while` `(n !``=` `0``):``        ``r ``=` `n ``%` `10` `        ``# Store the elements which are``        ``# divisible by two in stack1``        ``if` `(r ``%` `2` `=``=` `0``):``            ``stack1.append(r)` `        ``# Store the elements which are``        ``# not divisible by two in stack2.``        ``else` `:``            ``stack2.append(r)` `        ``n ``=` `n ``/``/` `10``    ``while` `(``len``(stack1) > ``0` `and` `len``(stack2) > ``0``):` `        ``# Concatenate the answer with smaller value``        ``# of the topmost elements of both the``        ``# stacks and then pop that element``        ``if` `(stack1[``-``1``] < stack2[``-``1``]):``            ``ans ``=` `ans ``*` `10` `+` `stack1[``-``1``]``            ``del` `stack1[``-``1``]` `        ``else``:``            ``ans ``=` `ans ``*` `10` `+` `stack2[``-``1``]``            ``del` `stack2[``-``1``]` `    ``# Concatenate the answer with remaining``    ``# values of stack1.``    ``while` `(``len``(stack1) > ``0``):``        ``ans ``=` `ans ``*` `10` `+` `stack1[``-``1``]``        ``del` `stack1[``-``1``]` `    ``# Concatenate the answer with remaining``    ``# values of stack2.``    ``while` `(``len``(stack2) > ``0``):``        ``ans ``=` `ans ``*` `10` `+` `stack2[``-``1``]``        ``del` `stack2[``-``1``]` `    ``return` `ans` `# Driver code``n1 ``=` `64432` `# Function calling``print``(minimumNo(n1))` `n2 ``=` `3137``print``(minimumNo(n2))` `# This code is contributed by mohit kumar 29`

## C#

 `// C# implementation of the above approach.``using` `System;``using` `System.Collections.Generic;` `class` `GFG``{``    ` `// Function to return the minimum number``static` `int` `minimumNo(``int` `n)``{``    ``int` `ans = 0;``    ``Stack<``int``> stack1 = ``new` `Stack<``int``>();``    ``Stack<``int``> stack2 = ``new` `Stack<``int``>();``    ``while` `(n != 0)``    ``{``        ``int` `r = n % 10;` `        ``// Store the elements which are``        ``// divisible by two in stack1``        ``if` `(r % 2 == 0)``        ``{``            ``stack1.Push(r);``        ``}` `        ``// Store the elements which are``        ``// not divisible by two in stack2.``        ``else``        ``{``            ``stack2.Push(r);``        ``}``        ``n = n / 10;``    ``}` `    ``while` `(stack1.Count != 0 && stack2.Count != 0)``    ``{` `        ``// Concatenate the answer with smaller value``        ``// of the topmost elements of both the``        ``// stacks and then pop that element``        ``if` `(stack1.Peek() < stack2.Peek())``        ``{``            ``ans = ans * 10 + stack1.Peek();``            ``stack1.Pop();``        ``}``        ``else``        ``{``            ``ans = ans * 10 + stack2.Peek();``            ``stack2.Pop();``        ``}``    ``}` `    ``// Concatenate the answer with remaining``    ``// values of stack1.``    ``while` `(stack1.Count != 0)``    ``{``        ``ans = ans * 10 + stack1.Peek();``        ``stack1.Pop();``    ``}` `    ``// Concatenate the answer with remaining``    ``// values of stack2.``    ``while` `(stack2.Count != 0)``    ``{``        ``ans = ans * 10 + stack2.Peek();``        ``stack2.Pop();``    ``}``    ``return` `ans;``}` `// Driver code``public` `static` `void` `Main(String[] args)``{``    ``int` `n1 = 64432;` `    ``// Function calling``    ``Console.Write(minimumNo(n1) + ``"\n"``);` `    ``int` `n2 = 3137;``    ``Console.Write(minimumNo(n2) + ``"\n"``);``}``}` `// This code is contributed by PrinciRaj1992`

## Javascript

 ``

Output:

```36442
3137```

Time Complexity: O(logN)
Auxiliary Space: O(logN).

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