# 168.Excel Sheet Column Title

**168.Excel Sheet Column Title**

难度:Easy

> 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 
    ...
Example 1:

Input: 1
Output: "A"
Example 2:

Input: 28
Output: "AB"
Example 3:

Input: 701
Output: "ZY"
```

实际上是26进制的数的转换，但是起始点是1开始，所以每次循环取模时，需要-1.

```
class Solution {
public:
    string convertToTitle(int n) {
        string res;
        while(n>26)
        {
            int t=(n-1)%26;
            cout<<t<<endl;
            res= char('A'+t) +res;
            n=(n-t)/26;
        }
    //    cout<<n<<endl;
        return char('A' +n-1) + res;
    }
};
```

> 执行用时 :4 ms, 在所有 C++ 提交中击败了72.89%的用户\
> 内存消耗 :8 MB, 在所有 C++ 提交中击败了63.84%的用户
