leetcode练习：5. Longest Palindromic Substring

/**
 * @param {string} s
 * @return {string}
 */
var longestPalindrome = function(s) {
    var res="";
    var len=s.length;
    var j,k;
    
    for(var i=0;i<len;i++){
        var cur="";
        j = i-1;
        k = i+1;
        
        cur += s[i];
        while(k <len && j >=0){
            if(s[j] == s[k]) {
                    var temp = s[j];
                    temp += cur;
                    cur = temp + s[j];               
            } else {
                break;
            }
            j--;
            k++;
        }
        if(cur.length >= res.length){
            res = cur;
        }
     }  
    
     for(var i=0;i<len;i++){
        cur="";
        j = i;
        k = i+1;
        while(k <len && j >=0){
            if(s[j] == s[k]) {
                var temp =s[j];
                temp += cur;
                temp += s[j];
      　　　　　　cur = temp;
            } else {
                break;
            }
            j--;
            k++;
        }
       console.log(cur,cur.length);
        if(cur.length >= res.length){
            res = cur;
        }          
     }
    return res;
};