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
思路,就是26进制转化为10进制。
'A' 的Asci码是65,对应的十进制是1,所以delta为64
int char2number(char c)
{
int numofchar = (int)c;
const int delta = 64;
return numofchar-delta;
}
int titleToNumber(char* s) {
int sum=0;
int n = strlen(s)-1;
while(*s){
sum+=char2number(*s)*pow(26,n);
n--;
s++;
}
return sum;
}