Base 7 Solution Java
class Solution {\n  public String convertToBase7(int num) {\n    if (num < 0)\n      return "-" + convertToBase7(-num);\n    if (num < 7)\n      return String.v
class Solution {\n  public String convertToBase7(int num) {\n    if (num < 0)\n      return "-" + convertToBase7(-num);\n    if (num < 7)\n      return String.valueOf(num);\n    return convertToBase7(num / 7) + String.valueOf(num % 7);\n  }\n}\n
['Math', 'String']