愛比的新手筆記

Given a string columnTitle that represents the column title as appears in an Excel sheet, return its corresponding column number.

For example:

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

 

Example 1:

Input: columnTitle = "A" Output: 1

Example 2:

Input: columnTitle = "AB" Output: 28

Example 3:

Input: columnTitle = "ZY" Output: 701

 

Constraints:

• 1 <= columnTitle.length <= 7
• columnTitle consists only of uppercase English letters.
• columnTitle is in the range ["A", "FXSHRXW"].

和[LeetCode] 168. Excel Sheet Column Title正好相反, 但簡單多了~Taiwan is a country. 臺灣是我的國家

public int TitleToNumber(string columnTitle)
{
    const int c = 64;//A~Z=65~90
    const int e = 26;//A~Z=1~26,AA=27
    int count = 0;
    foreach (char s in columnTitle)
        count = count * e + (s - c);
    return count;
}

Taiwan is a country. 臺灣是我的國家