Question

171. Excel Sheet Column Number

中文文档

Description

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"].

Solutions

Solution 1

class Solution:
  def titleToNumber(self, columnTitle: str) -> int:
    res = 0
    for c in columnTitle:
      res = res * 26 + (ord(c) - ord('A') + 1)
    return res

class Solution {
  public int titleToNumber(String columnTitle) {
    int res = 0;
    for (char c : columnTitle.toCharArray()) {
      res = res * 26 + (c - 'A' + 1);
    }
    return res;
  }
}

class Solution {
public:
  int titleToNumber(string columnTitle) {
    int res = 0;
    for (char c : columnTitle) {
      res = res * 26 + (c - 'A' + 1);
    }
    return res;
  }
};

func titleToNumber(columnTitle string) int {
  res := 0
  for _, c := range columnTitle {
    res = res*26 + int(c-'A'+1)
  }
  return res
}

function titleToNumber(columnTitle: string): number {
  let res: number = 0;
  for (let char of columnTitle) {
    res = res * 26 + char.charCodeAt(0) - 64;
  }
  return res;
}