171. Excel Sheet Column Number
Problem
Related to question Excel Sheet Column Title
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
问题
给定一个像Excel表单一样列标题,将其转化为数字。
例如:
A -> 1
B -> 2
C -> 3
…
Z -> 26
AA -> 27
AB -> 28
思路
本题本质上是二十六进制转十进制数,与二进制转十进制类似。
代码(C++)
class Solution {
public:
int titleToNumber(string s) {
int length = s.length();
int number = 0;
for (int i = 0;i<length-1;i++)
{
number = (number + s[i]-'A'+1)*26;
}
number += (s[length -1]-'A'+1);
return number;
}
};