## Algorithm

Problem Name: 171. Excel Sheet Column Number

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"]`

## Code Examples

### #1 Code Example with C Programming

```Code - C Programming```

``````
int titleToNumber(char* s) {
int k = 0;
while (s && *s) {
k = k * 26 + (*s) - 'A' + 1;
s ++;
`   }
return k;
}
``````
Copy The Code &

Input

cmd
columnTitle = "A"

Output

cmd
1

### #2 Code Example with C++ Programming

```Code - C++ Programming```

``````
class Solution {
public:
int titleToNumber(string s) {
int res = 0;
for(auto c: s){
res *= 26;
res += c - 'A' + 1;
}
return res;
}
};
``````
Copy The Code &

Input

cmd
columnTitle = "A"

Output

cmd
1

### #3 Code Example with Java Programming

```Code - Java Programming```

``````
class Solution {
public int titleToNumber(String columnTitle) {
int numericValue = 0;
int multiplier = 1;
for (int i = columnTitle.length() - 1; i >= 0; i--) {
int currCharNum = columnTitle.charAt(i) - 'A' + 1;
numericValue += multiplier * currCharNum;
multiplier *= 26;
}
return numericValue;
}
}
``````
Copy The Code &

Input

cmd
columnTitle = "AB"

Output

cmd
28

### #4 Code Example with Javascript Programming

```Code - Javascript Programming```

``````
const titleToNumber = function(s) {
const arr = s.split("");
const len = arr.length;
const uac = "A".charCodeAt(0);
return arr.reduce((ac, el, idx, arr) => {
return ac + Math.pow(26, len - idx - 1) * (`\${el}`.charCodeAt(0) - uac + 1);
}, 0);
};
``````
Copy The Code &

Input

cmd
columnTitle = "AB"

Output

cmd
28

### #5 Code Example with Python Programming

```Code - Python Programming```

``````
class Solution:
def titleToNumber(self, s):
"""
:type s: str
:rtype: int
"""
return sum([(ord(char)-64)*(26**i) for i,char in enumerate(s[::-1])])
``````
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Input

cmd
columnTitle = "ZY"

Output

cmd
701

### #6 Code Example with C# Programming

```Code - C# Programming```

``````
namespace LeetCode
{
public class _0171_ExcelSheetColumnNumber
{
public int TitleToNumber(string s)
{
var value = 0;
foreach (var ch in s)
{
value *= 26;
value += ch - 'A' + 1;
}

return value;
}
}
}
``````
Copy The Code &

Input

cmd
columnTitle = "ZY"

Output

cmd
701