Excel Sheet Column Number

This problem can be seen as a 26-in-one question. 26 binary means you can combine up to 26 different symbols to represent a numeric value.

Therefore, the value of the ABC Representative is: a*262+b*261+c*260=1*262+2*261+3*260, other letter combinations and so on.

The following method is a very intuitive idea, but to invoke the C + + library function pow (x,a), the calculation time will be longer.

The POW (x,a) can calculate the a power of X, and the ASCII code of ' a ' is 64.

classSolution { Public:    intTitletonumber (strings) {intN=s.size ()-1; intresult=0;  for(intI=0; i<=n;i++) {result+ = (s[i]- -) *pow ( -, N-i); }        returnresult; }};

A better notation is:

classSolution { Public:    intTitletonumber (strings) {intresult=0;  for(intI=0; I<s.size (); i++) Result=result* -+s[i]-'A'+1; returnresult; }};

Excel Sheet Column Number