Java Shifting Elements in an Array

Question

I have an array of objects in Java  and I am trying to pull one element to the top and shift the rest down by one   Assume I have an array of size 10  and I am trying to pull the fifth element  The fifth element goes into position 0 and all elements from 0 to 5 will be shifted down by one   This algorithm does not properly shift the elements   Object temp   pool position    for  int i   0  i  lt  position  i                          array i 1    array i     array 0    temp    How do I do it correctly

User · Answer

Try this   Object temp   pool position    for  int i   position-1  i  gt   0  i--                        array i 1    array i      array 0    temp    Look here to see it working  http   www ideone com 5JfAg

User · Answer

Logically it does not work and you should reverse your loop   for  int i   position-1  i  gt   0  i--                        array i 1    array i       Alternatively you can use  System arraycopy array  0  array  1  position

User · Answer

Manipulating arrays in this way is error prone  as you ve discovered  A better option may be to use a LinkedList in your situation  With a linked list  and all Java collections  array management is handled internally so you don t have to worry about moving elements around  With a LinkedList you just call remove and then addLast and the you re done

User · Answer

Write a Java program to create an array of 20 integers  and then implement the process of shifting the array to right for two elements  public class NewClass3             public static void main  String args                int a       1 2              int temp              for int i   0  i lt a length -1  i                     temp   a i            a i    a i 1            a i 1    temp                          for int p   a       System out print p

User · Answer

In the first iteration of your loop  you overwrite the value in array 1    You should go through the indicies in the reverse order

User · Answer

import java util Scanner   public class Shift        public static void main String   args             Scanner input   new Scanner  System in           int array     new int  5           int array1     new int  5           int i  temp           for  i 0  i lt 5  i                  System out printf  Enter array  d    n   i               array i    input nextInt      Taking input in the array                    System out println   nEntered datas are   n            for  i 0  i lt 5  i                  System out printf  array  d     d n   i  array i      This will show the data you entered  Not the shifting one                     temp   array 4     We declared the variable  temp  and put the last number of the array there             System out println   nAfter Shifting   n             for i 3  i gt  0  i--                array1 i 1    array i     New array is  array1   amp  Old array is  array   When array 4  then the value of array 3  will be assigned in it and this goes on               array1 0    temp    Finally the value of last array which was assigned in temp goes to the first of the new array                     for  i 0  i lt 5  i                  System out printf  array  d     d n   i  array1 i                       input close

User · Answer

static void pushZerosToEnd int arr            int n   arr length          int count   0      Count of non-zero elements            Traverse the array  If element encountered is non-zero  then            replace the element at index  count  with this element         for  int i   0  i  lt  n  i                 if  arr i     0  enter code here                    arr count      arr i      here count is incremented                 swapNumbers arr count   i                     for  int j   0  j  lt  n  j                 System out print arr j                              public static void swapNumbers int    arr  int pos1  int pos2           int temp    arr pos2           arr pos2    arr pos1           arr pos1    temp

User · Answer

Instead of shifting by one position you can make this function more general using module like this   int   original     1  2  3  4  5  6    int   reordered   new int original length   int shift   1   for int i 0  i lt original length i         reordered i    original  shift i  original length

User · Answer

Assuming your array is  10 20 30 40 50 60 70 80 90 100   What your loop does is   Iteration 1  array 1    array 0    10 10 30 40 50 60 70 80 90 100   Iteration 2  array 2    array 1    10 10 10 40 50 60 70 80 90 100   What you should be doing is  Object temp   pool position    for  int i    position - 1   i  gt   0  i--                        array i 1    array i      array 0    temp

User · Answer

You can just use Collections rotate List lt   gt  list  int distance   Use Arrays asList array  to convert to List   more info at  https   docs oracle com javase 7 docs api java util Collections html rotate java util List  20int

User · Answer

Just for completeness  Stream solution since Java 8   final String   shiftedArray   Arrays stream array           skip 1           toArray String    new     I think I sticked with the System arraycopy   in your situtation  But the best long-term solution might be to convert everything to Immutable Collections  Guava  Vavr   as long as those collections are short-lived

User · Answer

Another variation if you have the array data as a Java-List      listOfStuff add               0               listOfStuff remove listOfStuff size   - 1       Just sharing another option I ran across for this  but I think the answer from  Murat Mustafin is the way to go with a list

User · Answer

You can use the Below  codes for shifting not rotating       int   arr    1 2 3 4 5 6 7 8 9 10 11 12               int n   arr length              int d   3    Programm for shifting array of size n by d elements towards left       Input    1 2 3 4 5 6 7 8 9 10 11 12      Output   4 5 6 7 8 9 10 11 12 10 11 12           public void shiftLeft int   arr int d int n                for int i 0 i lt n-d i                      arr i    arr i d                             Programm for shifting array of size n by d elements towards right       Input    1 2 3 4 5 6 7 8 9 10 11 12      Output   1 2 3 1 2 3 4 5 6 7 8 9           public void shiftRight int   arr int d int n                 for int i n-1 i gt  d i--                    arr i    arr i-d

User · Answer

A left rotation operation on an array of size n shifts each of the array s elements  unit to the left  check this out        public class Solution       private static final Scanner scanner   new Scanner System in        public static void main String   args            String   nd   scanner nextLine   split                int n   Integer parseInt nd 0       no  of elements in the array          int d   Integer parseInt nd 1       number of left rotations          int   a   new int n           for int i 0 i lt n i               a i  scanner nextInt                     Solution s  new Solution           number of left rotations         for int j 0 j lt d j                   s rotate a n                  print the shifted array           for int i a  System out print i                 shift each elements to the left by one     public static void rotate int a   int n               int  temp a 0           for int i 0 i lt n i                 if i lt n-1  a i  a i 1                else a i  temp

User · Answer

public class Test1        public static void main String   args             int   x     1  2  3  4  5  6            Test1 test   new Test1            x   test shiftArray x  2           for  int i   0  i  lt  x length  i                  System out print x i                               public int   pushFirstElementToLast int   x  int position            int temp   x 0           for  int i   0  i  lt  x length - 1  i                  x i    x i   1                     x x length - 1    temp          return x             public int   shiftArray int   x  int position            for  int i   position - 1  i  gt   0  i--                x   pushFirstElementToLast x  position                     return x

[java] Java, Shifting Elements in an Array

Examples related to java

Examples related to arrays

Examples related to algorithm

Examples related to shift