LeetCode #20 Valid Parentheses with JavaScript

Solution to LeetCode's 20. Valid Parentheses with JavaScript.

Solution

/** * @param {string} s * @return {boolean} */ const isValid = (s) => { const map = { "(": ")", "[": "]", "{": "}", }; const stack = []; for (let i = 0; i < s.length; i++) { if (stack.length > 0 && map[stack[stack.length - 1]] === s[i]) { stack.pop(); } else { stack.push(s[i]); } } return stack.length === 0; }; 

• Time complexity: O(n)
• Space complexity: O(n)

1. save the target parentheses in an object with keys and values
2. add the string to the stack array in a for loop
3. if the closing parenthesis is a pair with the last value in the stack array, remove it from the stack array
4. return true if the stack array is finally empty, false if it remains