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
Iterative
class Solution {
public String convertToBase7(int num) {
if (num == 0) {
return "0";
}
StringBuilder sb = new StringBuilder();
String prefix = "";
if (num < 0) {
num = -num;
prefix = "-";
}
while (num > 0) {
sb.insert(0, num % 7);
num /= 7;
}
return prefix + sb.toString();
}
}
