Excel Sheet Column Title

Excel Sheet Column Title

 Total Accepted: 17772 Total Submissions: 100508

Question Solution 

Given a positive integer, return its corresponding column title as appear in an Excel sheet.

For example:

    1 -> A    2 -> B    3 -> C    ...    26 -> Z    27 -> AA    28 -> AB 

Credits:
Special thanks to @ifanchu for adding this problem and creating all test cases.

开始看到这个题目，最开始是凭直觉就往26进制方面去想：

while(n>0)        {            c=(n-1)%26+1;            n/=26;            cstr[len++]=c+'A'-1;        }

但是后来发现输入26的时候会输出AZ，这是因为，本来26进制是0~25,但是，这里应该是每位1~26，用n/=26的

方式并不能将26的低位舍弃，需要手动把低位减去，这样就可以了。

class Solution {public:    string convertToTitle(int n) {        int len=0,Count=1,c;        char cstr[100],temp;        while(n>0)        {            c=(n-1)%26+1;            n-=c;            n/=26;            cstr[len++]=c+'A'-1;        }        for(int i=0;i<len/2;i++)        {            temp=cstr[i];            cstr[i]=cstr[len-i-1];            cstr[len-i-1]=temp;        }        cstr[len]='\0';        return string(cstr);    }};