Mastering Parentheses Balance Checks in TypeScript

Dear TypeScript Enthusiasts,

In the realm of software development, certain fundamental challenges persist across various domains. One such timeless puzzle is checking for balanced parentheses. From parsing expressions to validating code syntax, the ability to determine if parentheses are correctly balanced is crucial.

Understanding the Problem

Consider an expression containing different types of parentheses: ({[]}). A balanced expression has every opening parenthesis matched and properly closed. Conversely, an unbalanced one, such as (({)}), contains mismatches, disrupting the balance.

Approaches to Tackle the Challenge

1. Stack-Based Approach:

Utilizing a stack data structure proves instrumental in solving this problem. As each opening parenthesis is encountered, it gets pushed onto the stack. When a closing parenthesis is found, it's compared to the top element on the stack. If they match, the opening parenthesis is popped, ensuring a balanced sequence.

2. Counters Method:

Another approach involves using counters to track the number of open and closed parentheses. By iterating through the expression, we maintain counts and ensure that each opening parenthesis has a corresponding closing one.

TypeScript Solution

function checkBalancedParentheses(expression: string): boolean {
    const stack: string[] = [];
    const pairs: { [key: string]: string } = { '(': ')', '[': ']', '{': '}' };

    for (const char of expression) {
        if (char in pairs) {
            stack.push(char);
        } else {
            const top = stack.pop();
            if (!top || pairs[top] !== char) {
                return false;
            }
        }
    }

    return stack.length === 0;
}

const isBalanced = checkBalancedParentheses("({[]})"); // Output: true

Real-World Applications

This problem transcends its simplicity and finds application in various domains. From validating mathematical expressions in parsers to ensuring syntactical correctness in code editors, the need for balanced parentheses checking persists.

Companies Embracing This Challenge

Frontend engineering interviews at tech giants like Google, Amazon, Microsoft, and startups such as Airbnb and Dropbox have included this problem to gauge a candidate's problem-solving skills and grasp of fundamental data structures.

Mastering the art of balancing parentheses in TypeScript not only showcases your understanding of algorithms but also serves as a foundational skill in software engineering.

So, TypeScript enthusiasts, venture into this challenge, enhance your problem-solving prowess, and fortify your TypeScript skills!

Happy Coding!