[LeetCode] Excel Sheet Column Title

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.

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(E) Excel Sheet Column Number

分析：本质上是10进制到26进制的转换，但是 由于下标从1开始而不是从0开始，因此要减一操作。

1 --》A
26--》Z

先取出余数，然后将其转换成字符A~Z，
然后n= （n-1）/26,将26进制的数右移一位，然后从新做判断。。

#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <vector>
#include <queue>
#include <stack>
#include <algorithm>
using namespace std;

void printArray(int *array, int size)
{
for(int i = 0; i < size; i++)
cout << array[i]<< "\t" ;
cout << endl;
}

void printVector(vector<int> array )
{
for(int i = 0; i <array.size(); i++)
cout << array[i]<< "\t" ;
cout << endl;
}

class Solution {
public:
string convertToTitle(int n) {
string str;
int a = 0;
while(n)
{
a = (n-1) % 26;
str += char(a + 'A');
n = (n-1)/26;
}
reverse(str.begin(), str.end());
return str;
}
};

#if 0
1 -> A
2 -> B
3 -> C
...
26 -> Z
27 -> AA
28 -> AB
#endif

int main()
{
Solution sl;
cout << sl.convertToTitle(1) <<endl;
cout << sl.convertToTitle(100) <<endl;
cout << sl.convertToTitle(1000) <<endl;

cout << endl;
return 0;
}