Tag: string

Categories
Leetcode Recursion String

Look and Say

let lookAndSay = function(nth, number = "1") {
    if (nth === 1) return number;

    let index = 0,
        counter = 1,
        currentNumber = "";

    let result = "";
    while (index < number.length) {
        if (index === 0) {
            currentNumber = number[index];
        }
        else if (currentNumber === number[index]) {
            counter++;
        }
        else if (currentNumber !== number[index]) {
            result = `${result}${counter}${currentNumber}`;//?
            counter = 1;
            currentNumber = number[index];
        }

        index++;
    }

    result = `${result}${counter}${currentNumber}`;//?

    return lookAndSay(--nth, result);
}
Categories
Leetcode Parenthesis String

Valid Parenthesis

function validParenthesis(str) {

    let closingMap = {
        ')' : '(',
        ']' : '[',
        '}' : '{'
    }

    let chars = [];
    for(let i = 0; i < str.length; i++) {
        if (str[i] === '(' || str[i] === '[' || str[i] === '{') {
            chars.push(str[i]);
        }
        else {
            let compare = chars.pop();
            if (closingMap[str[i]] !== compare) return false;
        }
    }
    return chars.length === 0;
}