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 <= 7columnTitleconsists only of uppercase English letters.columnTitleis 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;
}
Input
Output
#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;
}
};
Input
Output
#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;
}
}
Input
Output
#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);
};
Input
Output
#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])])
Input
Output
#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;
}
}
}
Input
Output