Formatted question description: https://leetcode.ca/all/504.html
504. Base 7
Level
Easy
Description
Given an integer, return its base 7 string representation.
Example 1:
Input: 100
Output: “202”
Example 2:
Input: -7
Output: “-10”
Note: The input will be in range of [-1e7, 1e7].
Solution
If nums is 0, simply return “0”.
Otherwise, split the sign out and deal with the absolute value of num. Each time divide num by 7 and store the remainders in the reverse order until num becomes 0. If num is negative initially, add the negative sign. Finally return the string of base 7 representation.
class Solution {
public String convertToBase7(int num) {
if (num == 0)
return "0";
int sign = num >= 0 ? 1 : -1;
num = Math.abs(num);
StringBuffer base7 = new StringBuffer();
while (num > 0) {
int remainder = num % 7;
base7.insert(0, (char) (remainder + '0'));
num /= 7;
}
if (sign < 0)
base7.insert(0, '-');
return base7.toString();
}
}