# 171. Excel Sheet Column Number

## 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

• 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;
}
};

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


• public class Solution {
public int TitleToNumber(string columnTitle) {
int ans = 0;
foreach (char c in columnTitle) {
ans = ans * 26 + c - 'A' + 1;
}
return ans;
}
}