# 168. Excel Sheet Column Title

## 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

• 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();
}
}

• 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])


• func convertToTitle(columnNumber int) string {
res := []rune{}
for columnNumber != 0 {
columnNumber -= 1
res = append([]rune{rune(columnNumber%26 + int('A'))}, res...)
columnNumber /= 26
}
return string(res)
}

• 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('');
}


• 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());
}
}

• impl Solution {
pub fn convert_to_title(column_number: i32) -> String {
let mut ret = String::from("");
let mut column_number = column_number;

while column_number > 0 {
if column_number <= 26 {
ret.push((('A' as u8) + (column_number as u8) - 1) as char);
break;
} else {
let mut left = column_number % 26;
left = if left == 0 { 26 } else { left };
ret.push((('A' as u8) + (left as u8) - 1) as char);
column_number = (column_number - 1) / 26;
}
}

ret.chars().rev().collect()
}
}