valid-parenthesis.js

// https://leetcode.com/problems/valid-parentheses/solution/

/**
 * @param {string} s
 * @return {boolean}
 */
function isValid(s) {
    const stack = []
    const open = {
        "(": true,
        "{": true,
        "[": true
    }
    const corresponding = {
        ")": "(",
        "}": "{",
        "]": "["
    }
    
    for (let i = 0; i < s.length; i++) {
        if (open[s[i]]) {
            stack.push(s[i])
        } else if (stack.length == 0) {
            return false
        } else if (corresponding[s[i]] == stack[stack.length - 1]) {
            stack.pop()
        } else {
            return false
        }
    }
    return stack.length == 0
};
// is this an open?
/*
Edge Case - Check the length of the string / Can

1. Create a stack variable
2. Create hash with characters 
3. For loop - iterate through string
4. Push open char into stack (if you encounter opening char)
5. Pop the opening char off the stack if the corresponding char in the string 
*/