PROBLEM DESCRIPTION
Given a column title A as appears in an Excel sheet, return its corresponding column number.
SOLUTION
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public class Solution {
public int titleToNumber(String A) {
int res = 0;
int n = A.length();
// Iterate through each character in reverse order
for(int i=n-1; i>=0; i--){
// Extract the current character
char ch = A.charAt(i);
// Calculate the numeric value of the character (A=1, B=2, C=3 etc.)
int chVal = ch - 'A' + 1;
// Calculate the power of 26 based on the position of the character in the title
int pow = n-i-1;
// Update the result by adding the product of character value and 26 raised to the power
res = res + chVal * (int) Math.pow(26, pow);
}
return res;
}
}