Question

171. Excel 表列序号

English Version

题目描述

给你一个字符串 columnTitle ，表示 Excel 表格中的列名称。返回 _该列名称对应的列序号_ 。

例如：

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

 

示例 1:

输入: columnTitle = "A"
输出: 1

示例 2:

输入: columnTitle = "AB"
输出: 28

示例 3:

输入: columnTitle = "ZY"
输出: 701

 

提示：

• 1 <= columnTitle.length <= 7
• columnTitle 仅由大写英文组成
• columnTitle 在范围 ["A", "FXSHRXW"] 内

解法

方法一

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;
}