最長重複文字列なし

import java.util.HashSet;

/**
 *        
 * Created by 76549 on 2019-05-15.
 */
public class LongStr {
    /**
     *              
     * @param s
     * @return
     */
    public static String longNonRecurString(String s) {
        int begin=0;
        int ans=0;
        for (int i = 0; i < s.length(); i++) {
            for (int j = i+1; j < s.length(); j++) {
                String subs=s.substring(i,j);
                if(isNoRecurstr(subs)){
                    if(j-i>ans){
                        ans=j-i;
                        begin=i;
                    }
                    ans=Math.max(ans,j-i);
                }
            }
        }
        return  s.substring(begin,begin+ans);
    }
    /**
     *                  
     * @param str
     * @return
     */
    public static boolean isNoRecurstr(String str){
        HashSet h=new HashSet();
        for(int i=0;i h=new HashSet();
        while(i