Decode Uppercase Spreadsheet Column Titles
Company: Google
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: easy
Interview Round: Other
### Problem
Convert an uppercase spreadsheet column title to its positive column number. Letters represent digits A=1 through Z=26: after Z comes AA=27, AB=28, and so on.
```cpp
int titleToNumber(string columnTitle);
```
### Examples
```text
Input: columnTitle = "AZ"
Output: 52
```
```text
Input: columnTitle = "AAA"
Output: 703
```
### Constraints
- Length is between 1 and 7.
- Only uppercase English letters occur.
- The title lies from A through FXSHRXW in spreadsheet column-number order, inclusive.
Overview: Decode uppercase spreadsheet titles with one-based base-26 digits and the source’s exact title bound.