20210119.md

Algorithm

168. Excel Sheet Column Title

Description

Given a positive integer, return its corresponding column title as appear in an Excel sheet.

For example:

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

Example 1:

Input: 1
Output: "A"

Example 2:

Input: 28
Output: "AB"

Example 3:

Input: 701
Output: "ZY"

Solution

class Solution {
  public String convertToTitle(int n) {
        String ret = "";
        while(n!=0) {
        	ret = (char)((n-1)%26+'A')+ret;
        	n = (n-1)/26;
        }
        return ret;
    }
}

class Solution {
    public String convertToTitle(int n) {
        StringBuilder sb = new StringBuilder();
        int letter;
        while(n>0){
            letter = (n-1) % 26;
            sb.append((char)(letter+65));
            n = (n-1) / 26;
        }
        return sb.reverse().toString();
    }
}

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