Programming Riddle: How might you translate an Excel column name to a number?

Question

I was recently asked in a job interview to resolve a programming puzzle that I thought it would be interesting to share. It\'s about translating Excel column letters to actu

Answer 1

Wikipedia has good explanations and algos

http://en.wikipedia.org/wiki/Hexavigesimal

public static String toBase26(int value){
    // Note: This is a slightly modified version of the Alphabet-only conversion algorithm

    value = Math.abs(value);
    String converted = "";

    boolean iteration = false;

    // Repeatedly divide the number by 26 and convert the
    // remainder into the appropriate letter.
    do {
        int remainder = value % 26;

        // Compensate for the last letter of the series being corrected on 2 or more iterations.
        if (iteration && value < 25) {
            remainder--;
        }

        converted = (char)(remainder + 'A') + converted;
        value = (value - remainder) / 26;

        iteration = true;
    } while (value > 0);

    return converted;    
}