Program: Detect and remove loop in a LinkedList.

package com.java2novice.algos;

public class DeleteLinkedListLoop {

    static class Node {
        int data;
        Node next;
        Node(int tmp) {data = tmp;}
    }

    public static void main(String[] a){

        Node n1 = new Node(34);
        Node n2 = new Node(25);
        Node n3 = new Node(31);
        Node n4 = new Node(56);
        Node n5 = new Node(45);
        n1.next = n2;
        n2.next = n3;
        n3.next = n4;
        n4.next = n5;
        n5.next = n3;

        System.out.println("Loop detected: "+identifyAndDeleteLoop(n1));
        printLinkedList(n1);
    }

    static boolean identifyAndDeleteLoop(Node head) {

        /**
         * In this method, we will keep track of two pointers.
         * One pointer moves one step at a time and second one two steps.
         * If both pointers are same at any iteration, then the loop exists.
         * Then call the method to break the loop.
         */
        Node slowMv = head;
        Node fastMv = head;
        while (slowMv != null && fastMv != null && fastMv.next != null) {
            slowMv = slowMv.next;
            fastMv = fastMv.next.next;
            if(slowMv == fastMv) {
                breakLoop(slowMv, head);
                return Boolean.TRUE;
            }
        }
        return Boolean.FALSE;
    }

    static void breakLoop(Node loop, Node head) {

        Node p1 = loop;
        Node p2 = loop;
        int count=1;
        // count number of nodes on the loop
        while(p1.next != p2) {
            p1 = p1.next;
            count++;
        }
        // fix the pointer to head
        p1 = head;
        // another point is K nodes after head
        p2 = head;
        for(int i=0;i<count;i++) {
            p2 = p2.next;
        }
        // move both pointers at same pace so that they meet at loop starting node
        while (p1 != p2) {
            p1 = p1.next;
            p2 = p2.next;
        }
        // get pointer to the last node
        while(p2.next != p1) {
            p2 = p2.next;
        }
        // set the last node next value to null
        p2.next = null;
    }

    static void printLinkedList(Node head) {
        while(head != null) {
            System.out.print(head.data+" ");
            head = head.next;
        }
    }
}

Loop detected: true
34 25 31 56 45