Algorithm
Problem Name: 1047. Remove All Adjacent Duplicates In String
You are given a string s consisting of lowercase English letters. A duplicate removal consists of choosing two adjacent and equal letters and removing them.
We repeatedly make duplicate removals on s until we no longer can.
Return the final string after all such duplicate removals have been made. It can be proven that the answer is unique.
Example 1:
Input: s = "abbaca" Output: "ca" Explanation: For example, in "abbaca" we could remove "bb" since the letters are adjacent and equal, and this is the only possible move. The result of this move is that the string is "aaca", of which only "aa" is possible, so the final string is "ca".
Example 2:
Input: s = "azxxzy" Output: "ay"
Constraints:
1 <= s.length <= 105sconsists of lowercase English letters.
Code Examples
#1 Code Example with Java Programming
Code -
Java Programming
class Solution {
public String removeDuplicates(String s) {
Stack stack = new Stack<>();
for (char c : s.toCharArray()) {
if (!stack.isEmpty() && stack.peek() == c) {
stack.pop();
} else {
stack.push(c);
}
}
StringBuilder sb = new StringBuilder();
while (!stack.isEmpty()) {
sb.append(stack.pop());
}
return sb.reverse().toString();
}
}
Input
Output
#2 Code Example with Javascript Programming
Code -
Javascript Programming
const removeDuplicates = function(S) {
const queue = []
for(let i = 0; i < S.length; i++) {
if(queue.length > 0 && queue[queue.length - 1] === S[i]) {
queue.pop()
} else {
queue.push(S[i])
}
}
return queue.join('')
};
Input
Output
#3 Code Example with Python Programming
Code -
Python Programming
class Solution:
def removeDuplicates(self, S: str) -> str:
stack = []
for s in S:
if stack and stack[-1] == s:
stack.pop()
else:
stack.append(s)
return ''.join(stack)
Input
Output
#4 Code Example with C# Programming
Code -
C# Programming
using System.Text;
namespace LeetCode
{
public class _1047_RemoveAllAdjacentDuplicatesInString
{
public string RemoveDuplicates(string S)
{
var sb = new StringBuilder();
foreach (var ch in S)
{
if (sb.Length > 0 && sb[sb.Length - 1] == ch)
sb.Remove(sb.Length - 1, 1);
else
sb.Append(ch);
}
return sb.ToString();
}
}
}
Input
Output