leetcode:171 Excel Sheet Column number-daily Programming question tenth

Excel Sheet Column NumberTotal accepted:54683 Total submissions:140674 difficulty:easy

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

For example:

    1,    B, 2    C-3    ...    27 AA, Z    
Ideas:
Suppose num is a five-digit ABCDE.
num=a*26^4+b*26^3+c*26^2+d*26+e*1;
Radix as a base, initialized to 1, each cycle *26;

1 classSolution {2  Public:3     intTitletonumber (strings) {4         intlen=s.length ();5         if(len==0){6             return 0;7         }8         intnum=0;9         intradix=1;Ten          for(inti=len-1; i>=0; i--){ Onenum+=radix* (s[i]-'A'+1); Aradix*= -; -         } -         returnnum; the     } -};

leetcode:171 Excel Sheet Column number-daily Programming question tenth