paired-parentheses

Question

given a string of characters return a boolean indicating whether or not the string has well-formed parentheses.

input:

(david)((abby))

Output:

TRUE

Solution

The way we can solve is using a counter, where we can increment a counter if we find an opening parentheses and decrement if we encounter a closing parentheses.

Javascript

const pairedParentheses = (str) => {
  let count = 0;
  for (const char of str) {
    if (char === "(") {
      count++;
    } else if (char === ")") {
      if (count === 0) return false;
      count--;
    }
  }
  return count === 0;
};

Java

Concepts

Stacks

Patterns

• iterator