647. Palindromic Substrings

没啥特别 会longest palindromic substrings就可以

 

 

class Solution {
    int count = 0;
    int lo = 0;
    public int countSubstrings(String s) {
        if(s == "") return 0;
        if(s.length() < 2) return 1;
        for(int i = 0; i < s.length(); i++) {
            extendPalin(s, i, i);
            extendPalin(s, i, i+1);    
        }
        
        return count;
        
    }
    
    public void extendPalin(String s, int i, int j) {
        while(i >= 0 && j < s.length() && s.charAt(i) == s.charAt(j)) {
            i--;
            j++;
            count++;
        }
   
    }  
}class Solution {
    int count = 0;
    int lo = 0;
    public int countSubstrings(String s) {
        if(s == "") return 0;
        if(s.length() < 2) return 1;
        for(int i = 0; i < s.length(); i++) {
            extendPalin(s, i, i);
            extendPalin(s, i, i+1);    
        }
        
        return count;
        
    }
    
    public void extendPalin(String s, int i, int j) {
        while(i >= 0 && j < s.length() && s.charAt(i) == s.charAt(j)) {
            i--;
            j++;
            count++;
        }
   
    }  
}