此篇文章為我的解題紀錄，程式碼或許並不是很完善

Leetcode - 171. Excel Sheet Column Number

解題思路

從最左邊開始逐一運算，將char轉換成ascii code後乘上26的次方

我滴程式碼

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class Solution {
public:
    int titleToNumber(string columnTitle) {
        int size = columnTitle.length() - 1;
        int sum = 0;
        while(size > -1)
        {
            sum += pow(26, size)*((columnTitle[columnTitle.length() - 1 - size] - 'A') + 1);
            size--;
        }
        
        return sum;
    }
};
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class Solution:
    def titleToNumber(self, columnTitle: str) -> int:
        length = len(columnTitle)
        size = length - 1
        sum = 0
        while(size > -1):
            sum = sum + math.pow(26, size) * int( ord(columnTitle[length - 1 - size]) - 64 )
            size = size - 1
        
        return int(sum)