Write a
program to do the following:- Read an integer n. (where can be at most
50.) then
read n
integers one by one and store them in array data from,
index 0
to n-1. Now we are to rearrange the integers in data in the following ways:-
Find
the maximum value in data and put it in the center of the array (that is at
n/2),
find
the next largest value and put it to its right, and so on alternating right and
left until
all integers in data are done. For example if the array is initially:
Sample:
Give the number of integers: 6
INPUT: 5 1 9 8 2 4
OUTPUT: 2 5 9 8 4 1
pos = (array_length%2==0)? (array_length/2-1):(array_length/2);
To uderstand it consider the following input:
Give the number of integers: 6
INPUT: 5 1 9 8 2 4
Since 6 is even, pos = 6/2-1=2
After sorting the array it becomes
9 8 5 4 2 1
Now the first element '9' goes at position 0 of new array.
Now these elements 8[1], 5[2],4[3],2[4],1[5] of need to be inserted old array
where a[b] represent value at position b.
New array at this point looks like:
Empty[0],Empty[1],9[2],Empty[3],Empty[4],Empty[5]
Now 8[1] will go at Empty[3]
5[2] will got at Empty[1]
4[3] will go at Empty[4]
2[4] will go at Empty[0]
1[5] will go at Empty[5]
See that elements at odd position goes at position pos+right
1 ----- 2+1
3 ----- 2+2
5 ----- 2+3
So, it seems obvious to declare a right counter to 1 and increment it by 1 for the next step.
Similar arguments, goes for elements at even position.
The following code carries out this process.
int pos,right=1,left=1;
pos = (array_length%2==0)? (array_length/2-1):(array_length/2);
final_arr[pos]=arr[0];
for(int t=1;t<=array_length-1;t++) {
if(t%2 != 0) {
final_arr[pos+right]=arr[t];
right++;
}
else {
final_arr[pos-left]=arr[t];
left++;
}
}
JAVA CODE
import java.util.*;
public class ISC2002Q2 {
public static void main(String[] args) {
int N;
Scanner in = new Scanner(System.in);
do {
System.out.println("Enter the value of N
(<=50):");
N = in.nextInt();
if(N >50)
System.out.println("INVALID INPUT,TRY
AGAIN");
}while(N>50);
Array obj = new Array(N);
System.out.println("Enter the elements of the array:");
obj.inputArray();
System.out.println("Entered elements of the array:");
obj.display();
obj.generateNewArray();
in.close();
}
}
class Array {
public void generateNewArray() {
int temp;
//
sort the array in descending order
for(int i = 0; i < array_length; i++) {
for(int j=1; j < (array_length-i); j++) {
if(arr[j-1] <
arr[j]) {
temp = arr[j-1];
arr[j-1] = arr[j];
arr[j] = temp;
}
}
}
// putting
the elements at required position
int pos,right=1,left=1;
pos = (array_length%2==0)? (array_length/2-1):(array_length/2);
final_arr[pos]=arr[0];
for(int t=1;t<=array_length-1;t++) {
if(t%2 != 0)
{
final_arr[pos+right]=arr[t];
right++;
}
else {
final_arr[pos-left]=arr[t];
left++;
}
}
// displaying
the new array
System.out.println();
System.out.println("Array after required insertion:");
for(int i=0;i<array_length;i++)
System.out.print(final_arr[i]+" ");
}
public void display() {
for(int i=0;i<array_length;i++)
System.out.print(arr[i]+" ");
}
public void inputArray() {
Scanner in = new Scanner(System.in);
for(int i=0;i<array_length;i++)
arr[i]=in.nextInt();
in.close();
}
Array(int N) {
array_length = N;
arr = new int[array_length];
final_arr = new int[array_length];
}
private int array_length;
private int[] arr;
private int[] final_arr;
}
