Given a string str containing only characters x and y, the task is to perform the following operations while possible:
Find an index such that s[i] = ‘x’ and s[i+1] = ‘y’ and delete both the characters s[i] and s[i+1], if no such index is found then find an index such that s[i] = ‘y’ and s[i+1] = ‘x’ and swap(s[i], s[i+1]).
Print the final string after performing the given operation.
Examples:
Input: str = “xyyxx”
Output: x
Step 1: yxx (xy got deleted)
Step 2: xyx (yx got swapped)
Step 3: x (xy got deleted)Input: str = “xxyyxyy”
Output: y
Approach: In the final string there will be either only x or only y because if we have both x and y in the string then there would be a point where we have either xy or yx as sub-string.
- If it’s xy, we delete it straight away.
- If it is yx, we reverse it to get xy and then delete it.
Since in each deletion step, one x and one y gets deleted, the final string would have min(x, y) number of x and y characters deleted.
Below is the implementation of the above approach:
C++
// C++ implementation of the approach#include <bits/stdc++.h>using namespace std;// Function to return the modified stringstring printFinalString(string s){ int i, n; n = s.length(); int x = 0, y = 0; for (i = 0; i < n; i++) { // Count number of 'x' if (s[i] == 'x') x++; // Count number of 'y' else y++; } string finalString = ""; // min(x, y) number of 'x' and 'y' will be deleted if (x > y) for (i = 0; i < x - y; i++) finalString += "x"; else for (i = 0; i < y - x; i++) finalString += "y"; return finalString;}// Driver Program to test above functionint main(){ string s = "xxyyxyy"; cout << printFinalString(s);} |
Java
// Java implementation of the approachclass GFG{// Function to return the modified Stringstatic String printFinalString(String s) { int i, n; n = s.length(); int x = 0, y = 0; for (i = 0; i < n; i++) { // Count number of 'x' if (s.charAt(i) == 'x') { x++; } // Count number of 'y' else { y++; } } String finalString = ""; // min(x, y) number of 'x' and // 'y' will be deleted if (x > y) { for (i = 0; i < x - y; i++) { finalString += "x"; } } else { for (i = 0; i < y - x; i++) { finalString += "y"; } } return finalString;}// Driver Codepublic static void main(String args[]){ String s = "xxyyxyy"; System.out.println(printFinalString(s));}}// This code is contributed // by 29AjayKumar |
Python3
# Python 3 implementation of the approach# Function to return the modified stringdef prFinalString(s): i, n = 0, 0 n = len(s) x, y = 0, 0 for i in range(0, n): # Count number of 'x' if (s[i] == 'x'): x += 1 # Count number of 'y' else: y += 1 finalString = "" # min(x, y) number of 'x' and # 'y' will be deleted if (x > y): for i in range(0, x - y): finalString += "x" else: for i in range(0, y - x): finalString += "y" return finalString# Driver Codeif __name__ == '__main__': s = "xxyyxyy" print(prFinalString(s))# This code contributed by 29AjayKumar |
C#
// C# implementation of the approachusing System;class GFG{// Function to return the modified Stringstatic string printFinalString(string s) { int i, n; n = s.Length; int x = 0, y = 0; for (i = 0; i < n; i++) { // Count number of 'x' if (s[i] == 'x') { x++; } // Count number of 'y' else { y++; } } string finalString = ""; // min(x, y) number of 'x' and // 'y' will be deleted if (x > y) { for (i = 0; i < x - y; i++) { finalString += "x"; } } else { for (i = 0; i < y - x; i++) { finalString += "y"; } } return finalString;}// Driver Codepublic static void Main(){ string s = "xxyyxyy"; Console.WriteLine(printFinalString(s));}}// This code is contributed // by Akanksha Rai |
PHP
<?php// PHP implementation of the approach// Function to return the modified stringfunction printFinalString($s){ $n = strlen($s); $x = 0; $y = 0; for ($i = 0; $i < $n; $i++) { // Count number of 'x' if ($s[$i] == 'x') $x++; // Count number of 'y' else $y++; } $finalString = (string)null; // min(x, y) number of 'x' and 'y' will be deleted if ($x > $y) for ($i = 0; $i < $x - $y; $i++) $finalString .= "x"; else for ($i = 0; $i < $y - $x; $i++) $finalString .= "y"; return $finalString;}// Driver Code$s = "xxyyxyy";echo printFinalString($s);// This code is contributed by ihritik?> |
Javascript
<script>// Javascript implementation of the approach// Function to return the modified stringfunction printFinalString(s){ var i, n; n = s.length; var x = 0, y = 0; for (i = 0; i < n; i++) { // Count number of 'x' if (s[i] == 'x') x++; // Count number of 'y' else y++; } var finalString = ""; // min(x, y) number of 'x' and 'y' will be deleted if (x > y) for (i = 0; i < x - y; i++) finalString += "x"; else for (i = 0; i < y - x; i++) finalString += "y"; return finalString;}// Driver Program to test above functionvar s = "xxyyxyy";document.write( printFinalString(s));// This code is contributed by famously.</script> |
Output
y
Time Complexity: O(n), where n is the length of the given string.
Auxiliary Space: O(n), where n is the length of the given string.
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