如何判断一个链表是否有环路

转自

http://www.iteye.com/topic/1114110

 

public static boolean hasLoop(Node root) {
    r1 = root.clone();
               r2 = root.clone();
               while(true){
                   if(r1.hashnext){r1 = r1.next();}else{break;}
                   if(r1.hashnext){r1 = r1.next();}else{break;}

                   if(r2.hashnext){r2 = r2.next();}else{break;}

                   if(r1 == r2 ) return true;

               }


    return false;
}