Given an integer, return its base 7 string representation.

Example 1:

Input: 100Output: "202"

 

Example 2:

Input: -7Output: "-10"

 

Note: The input will be in range of [-1e7, 1e7].

 

1 public class Solution { 2     public String convertToBase7(int num) { 3         if (num == 0) return "0"; 4          5         StringBuffer result = new StringBuffer(); 6         Boolean isNegative = false; 7         if (num < 0) { 8             isNegative = true; 9             num = -num;10         }11         12         while (num != 0) {13             int insertMe = num % 7;14             result.insert(0, Integer.toString(insertMe));15             num /= 7;16         }17         if (isNegative) result.insert(0, "-");18         return result.toString();19     }20 }

 

1 public class Solution { 2     public String convertToBase7(int num) { 3         if (num == 0) return "0"; 4          5         Boolean isNegative = num < 0; 6         num = Math.abs(num); 7          8         String result = ""; 9         while (num != 0) {10             result = Integer.toString(num % 7) + result;11             num /= 7;12         }13         return isNegative ? "-" + result : result;14     }15 }