Excel Sheet Column Title : Accepted

Author: gouthampradhan

README.md

@@ -145,6 +145,7 @@ My accepted leetcode solutions to some of the common interview problems.
 - [Rotate Function](problems/src/math/RotateFunction.java) (Medium)
 - [Water and Jug Problem](problems/src/math/WaterAndJugProblem.java) (Medium)
 - [Add Digits](problems/src/math/AddDigits.java) (Easy)
+- [Excel Sheet Column Title](problems/src/math/ExcelSheetColumnTitle.java) (Easy)
 
 #### [Stack](problems/src/stack)
 

problems/src/math/ExcelSheetColumnTitle.java

@@ -0,0 +1,45 @@
+package math;
+
+/**
+ * Created by gouthamvidyapradhan on 12/08/2017.
+ * Given a positive integer, return its corresponding column title as appear in an Excel sheet.
+
+ For example:
+
+ 1 -> A
+ 2 -> B
+ 3 -> C
+ ...
+ 26 -> Z
+ 27 -> AA
+ 28 -> AB
+ */
+public class ExcelSheetColumnTitle {
+
+    private static final String CONST = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+    /**
+     * Main method
+     * @param args
+     * @throws Exception
+     */
+    public static void main(String[] args) throws Exception{
+        System.out.println(new ExcelSheetColumnTitle().convertToTitle(52));
+    }
+
+
+    public String convertToTitle(int n) {
+        StringBuilder ans = new StringBuilder();
+        while(n > 0){
+            int mod = n % 26;
+            n /= 26;
+            if(mod == 0){
+                ans.append('Z');
+                n -= 1;
+            }else{
+                ans.append(CONST.charAt(mod - 1));
+            }
+        }
+        return ans.reverse().toString();
+    }
+
+}