A phrase is a palindrome if, after converting all uppercase letters into lowercase letters and removing all non-alphanumeric characters, it reads the same forward and backward. Alphanumeric characters ...
//DP 思路:P[i][j]是记录i到j子串是不是回文串。P(i,j)={true,if the substring Si…Sj is a palindrome;false,if the substring Si…Sj is not a palindrome}。那么可以得到: ...