问题 ​​https://leetcode-cn.com/problems/excel-sheet-column-number/​​

练习使用JavaScript解答

/**
 * @param {string} s
 * @return {number}
 */
var titleToNumber = function(s) {
    var i,sum = 0;
    for(i=0;i<s.length;++i) {
        sum *= 26;
        sum += s.charCodeAt(i) - 64;
    }
    return sum;
};