171. Excel表列序号
题目其实就是转换26进制,26n∗mn+26n−1∗mn−1+...+26∗m126^n*m_n+26^{n-1} * m_ {n-1} +...+26*m_126n∗mn+26n−1∗mn−1+...+26∗m1, n为字母位数,m为每一位字母与A字母-1的差值。
class Solution {
public int titleToNumber(String s) {
char[] ss = s.toCharArray();
int n = ss.length-1;
int square;
int total = 0;
for(int i=0; i<ss.length; i++){
square = (int)Math.pow(26, n);
n--;
total += ((int)ss[i]-64)*square;
}
return total;
}
}