【中心扩展法】LCR_020_回文子串

求解代码

publicintcountSubstrings(Strings){if(s==null||s.length()==0){return0;}intans=0;for(inti=0;i<s.length();i++){// 1. 以i为中心（奇数长度回文）ans+=countPalindrome(s,i,i);// 2. 以i和i+1为中心（偶数长度回文）ans+=countPalindrome(s,i,i+1);}returnans;}privateintcountPalindrome(Strings,intleft,intright){intcount=0;while(left>=0&&right<s.length()&&s.charAt(left)==s.charAt(right)){count++;left--;right++;}returncount;}