_171.java

package com.fishercoder.solutions;

/**
 * 170. Two Sum III - Data structure design
 *
 * Given a column title as appear in an Excel sheet, return its corresponding column number.

 For example:

 A -> 1
 B -> 2
 C -> 3
 ...
 Z -> 26
 AA -> 27
 AB -> 28

 */
public class _171 {

  public static class Solution1 {
    public int titleToNumber(String s) {
      char[] c = s.toCharArray();
      int result = 0;
      for (int i = s.length() - 1; i >= 0; i--) {
        result +=
            (c[i] - 64) * ((int) Math.pow(26, s.length() - i - 1));//The ASCII value of A is 65
      }
      return result;
    }
  }
}