solution.js

/**
 * @param {string} s
 * @return {boolean}
 */
var validPalindrome = function(s) {
    let i = 0,
        j = s.length - 1,
        markedI = 0,
        markedJ = 0,
        leftSkip = false,
        rightSkip = false
    
    while (i < j) {
        if (s[i] === s[j]) {
            i++
            j--
        } else if (!leftSkip) {
            markedI = i
            markedJ = j
            i++
            leftSkip = true
        } else if (!rightSkip) {
            i = markedI
            j = markedJ
            j--
            rightSkip = true
        } else {
            return false
        }
    }
    
    return true
};