171. Excel Sheet Column Number

[Tcdian]

171. Excel Sheet Column Number

给定一个Excel表格中的列名称，返回其相应的列序号。

For example

    A -> 1
    B -> 2
    C -> 3
    ...
    Z -> 26
    AA -> 27
    AB -> 28 
    ...

Example 1

Input: "A"
Output: 1

Example 2

Input: "AB"
Output: 28

Example 3

Input: "ZY"
Output: 701

Note

• 1 <= s.length <= 7
• s consists only of uppercase English letters.
• s is between "A" and "FXSHRXW".

[Tcdian]

Solution

• JavaScript Solution

/**
 * @param {string} s
 * @return {number}
 */
var titleToNumber = function(s) {
    let result = 0;
    for (let i = s.length - 1; i >= 0; i--) {
        result += (s.codePointAt(i) - 64) * 26 ** (s.length - 1 - i);
    }
    return result;
};

• TypeScript Solution

function titleToNumber(s: string): number {
    let result = 0;
    for (let i = s.length - 1; i >= 0; i--) {
        result += (s.codePointAt(i) as number - 64) * 26 ** (s.length - 1 - i);
    }
    return result;
};