Leetcode 171. Excel表列序号 - 題解
Leetcode 171. Excel Sheet Column Number
線上送出:
https://leetcode.com/problems/excel-sheet-column-number/
Description
Given a column title as appear in an Excel sheet, return its corresponding column number.
For example:
A -> 1
B -> 2
C -> 3
...
Z -> 26
AA -> 27
AB -> 28
... 複制
Example 1:
Input: "A"
Output: 1 複制
Example 2:
Input: "AB"
Output: 28 複制
Example 3:
Input: "ZY"
Output: 701 複制
- Difficulty: Easy
- Total Accepted:174.7K
- Total Submissions:355.7K
- Contributor:ts
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Related Topics Math
Similar Questions Excel Sheet Column Title
思路:
這個問題實際上是要求将26進制字元串轉為10進制數字，可看成是多項式展開, 不同位的權weigh是26的不同的幂次方。
已AC代碼:
public class Solution
{
public int TitleToNumber(string s)
{
int len = s.Length;
int sum = 0;
int weigh = 1; // 該位的權, 26^0 ~ 26^(n-1)
for (int i = len; i >= 1; i--)
{
sum += (s[i - 1] - 'A' + 1) * weigh; // 從低位開始累加
weigh *= 26;
}
return sum;
}
} 複制
Rank:
You are here! Your runtime beats 99.39% of csharp submissions.