README_EN.md

168. Excel Sheet Column Title

中文文档

Description

Given an integer columnNumber, return its corresponding column title as it appears in an Excel sheet.

For example:

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

 

Example 1:

Input: columnNumber = 1
Output: "A"

Example 2:

Input: columnNumber = 28
Output: "AB"

Example 3:

Input: columnNumber = 701
Output: "ZY"

 

Constraints:

• 1 <= columnNumber <= 231 - 1

Solutions

Python3

class Solution:
    def convertToTitle(self, columnNumber: int) -> str:
        res = []
        while columnNumber:
            columnNumber -= 1
            res.append(chr(ord('A') + columnNumber % 26))
            columnNumber //= 26
        return ''.join(res[::-1])

Java

class Solution {
    public String convertToTitle(int columnNumber) {
        StringBuilder res = new StringBuilder();
        while (columnNumber != 0) {
            --columnNumber;
            res.append((char) ('A' + columnNumber % 26));
            columnNumber /= 26;
        }
        return res.reverse().toString();
    }
}

TypeScript

function convertToTitle(columnNumber: number): string {
    let res: string[] = [];
    while (columnNumber > 0) {
        --columnNumber;
        let num: number = columnNumber % 26;
        res.unshift(String.fromCharCode(num + 65));
        columnNumber = Math.floor(columnNumber / 26);
    }
    return res.join('');
}

C#

public class Solution {
    public string ConvertToTitle(int columnNumber) {
        StringBuilder res = new StringBuilder();
        while (columnNumber != 0) {
            --columnNumber;
            res.Append((char) ('A' + columnNumber % 26));
            columnNumber /= 26;
        }
        return new string(res.ToString().Reverse().ToArray());
    }
}

...