excelSheetColumnNumber

/*****************************/
Given a column title as appear in an Excel sheet, return its corresponding column number.

For example:

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

Input: "A"
Output: 1
Example 2:

Input: "AB"
Output: 28
Example 3:

Input: "ZY"
Output: 701
/***************************/
class Solution {
public:
	int titleToNumber(string s) {
		map<char, int>mpp = { {'A',1},{'B',2},{'C',3},{'D',4 } ,{'E',5} ,
		
		{ 'F',6 },{ 'G',7 },{ 'H',8 },{ 'I',9 } ,{ 'J',10 } ,
		{ 'K',11 },{ 'L',12 },{ 'M',13 },{ 'N',14 } ,{ 'O',15 } ,
		{ 'P',16 },{ 'Q',17 },{ 'R',18 },{ 'S',19 } ,{ 'T',20 } ,
		{ 'U',21 },{ 'V',22 },{ 'W',23 },{ 'X',24 } ,{ 'Y',25 } ,
		{'Z',26}
		};
		int size = s.length();
		int sum = 0;
		int count = size;
		for (int i = 0; i < size; i++) {
			sum += mpp[s[i]]*pow(26, count - 1);
			count = count - 1;
		}
		cout << sum << endl;
		return sum;
	}
};