collections - Java Challenge in LinkedList -

question 4: given integer array, convert linked list each node containing 1 sequence.

sample input : [1, 3, 4, 5, 8, 9, 11, 13, 14, 15, 16, 20, 23, 30,31,32] sample linked list : [1] -> [3,4,5] -> [8,9] -> [11] -> [13,14,15,16]->[20]->[23]->[30,31,32] 

the question may seems easy it's bit difficult answer.can write code above in java without using collection or linkedlist ?

below code detecting sequence (which might help).

class sequence {     public static string detectsequence(int seq[]) {         string result = "";         (int = 0; < seq.length - 1; i++) {             if (seq[i + 1] == seq[i] + 1) {                 result += seq[i] + " ";                 if (i != seq.length - 2) {                     if (seq[i + 1] != seq[i + 2] - 1) {                         result += seq[i + 1];                     }                 }             } else {                 result += " ";             }         }         if (seq[seq.length - 1] == seq[seq.length - 2] + 1) {             result += seq[seq.length - 1];         }         return result;     } } class question1 {     public static void main(string[] cla) {         int seqarray[] = {             4, 1, 2, 3, 4, 5, 8, 4, 7, 4, 5, 6, 7, 7, 7, 7, 7, 10, 11, 13, 1, 2, 3, 4         };         string res = sequence.detectsequence(seqarray);         system.out.println(res);     } } 

just give start...

public yourlinkedlist splittosequences(int[] array) {     yourlinkedlist list = new yourlinkedlist();      if(array.length > 0) {         yoursequence sequence = new yoursequence();         int currentnumber;         int lastnumber = array[0];         sequence.add(lastnumber);          for(int index = 1; index < array.length; index++) {             currentnumber = array[index];             if(currentnumber != lastnumber + 1) { // curentnumber breaks sequence                 list.add(sequence);               // save old sequence list                  sequence = new yoursequence();    // , start new 1             }             sequence.add(currentnumber);         }          list.add(sequence);     }     return list; } 

now go , figure out linked list , sequence classes , printing stuff...

a minimalistic implementation of linked list

public class mylinkedlist<t1> {     private mylinkedlistitem<t1> first = null;     private mylinkedlistitem<t1> last = null;      public mylinkedlist() {     }      public void add(t1 item) {         mylinkedlistitem<t1> newitem = new mylinkedlistitem<t1>(item);         if (first == null) {             first = newitem;         } else {             last.setnext(newitem);         }         last = newitem;     }      @override     public string tostring() {         stringbuffer buffer = new stringbuffer();          if(first != null) {             mylinkedlistitem<t1> current = first;              while(current.hasnext()) {                 buffer.append(current.tostring());                 buffer.append(" -> ");                 current = current.getnext();             }              buffer.append(current.tostring());         }          return buffer.tostring();     }      private class mylinkedlistitem<t2> {         private t2 data;         private mylinkedlistitem<t2> next = null;          public mylinkedlistitem(t2 data) {             this.data = data;         }          public boolean hasnext() {             return next != null;         }          public mylinkedlistitem<t2> getnext() {             return next;         }          public void setnext(mylinkedlistitem<t2> next) {             this.next = next;         }          @override         public string tostring() {             return data.tostring();         }     } }