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].
class Solution {
public:
string convertToBase7(int num) {
int symbol = 1;
string ans;
if(num < 0){
num = -num;
symbol = -1;
} else if(num == 0)
return "0";
while(num){
char rem = num % 7 + '0';
ans.insert(0, 1, rem);
num /= 7;
}
if(symbol == -1)
ans.insert(0, "-");
return ans;
}
};