LeetCode 504. Base 7

504. Base 7

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

题意即将一个十进制数转换成七进制数，并用字符串的形式返回。

我们可以先将其转换成七进制数字，然后利用

sprintf

将其转换成字符串形式，要注意负数特判，代码如下：

class Solution {
public:
string convertToBase7(int num) {
string rnt;
char rnt1[100];
int index = 0,numrnt = 0,flag = 0;
if (num < 0) {
flag = 1;
num = -num;
}
while (num) {
numrnt += (num % 7) * pow(10,index++);
num /= 7;
}
if (flag == 1) numrnt = -numrnt;
sprintf(rnt1,"%d",numrnt);
rnt = rnt1;
return rnt;
}
};