How to usea stack with for ..of loop in Javascript
In this approach, we are using a stack to find the length of the longest balanced subsequence in a string. It iterates through the string uses a stack to track opening parentheses and calculates the length of balanced subsequences.
Example: In this example, The balancedSubsequence function uses a stack to track open parenthesis positions in the string s. It calculates the length of the longest balanced subsequence and returns it.
function balancedSubsequence(s) {
const stack = [];
let maxmimum = 0;
let currentIndex = -1;
for (const char of s) {
currentIndex++;
char === '(' ? stack.push(currentIndex) :
char === ')' && stack.length > 0 ? (
stack.pop(),
maxmimum = Math.max(maxmimum, currentIndex -
(stack.length > 0
? stack[stack.length - 1] : -1))
) : null;
}
return maxmimum;
}
const input = "(()())";
console.log(balancedSubsequence(input));
Output
6
JavaScript Program to Find the Length of Longest Balanced Subsequence
In this article, we are going to learn about the Length of the Longest Balanced Subsequence in JavaScript. The Length of the Longest Balanced Subsequence refers to the maximum number of characters in a string sequence that can form a valid balanced expression, consisting of matching opening and closing brackets.
Example:
Input : S = "()())"
Output : 4
()() is the longest balanced subsequence
of length 4.
Input : s = "()(((((()"
Output : 4
We will explore all the above methods along with their basic implementation with the help of examples.
Table of Content
- Using a stack with for ..of loop
- Using Simple Counting
- Using Two Pointers