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/**

* Created by Devang on 19-Feb-17.

*/

public class ReverseArrayInPlace {

public static void main(String[] args) {

/* Read input and create array */

int n = 5;

int k = 3;

int [] array = {1, 2, 3, 4, 5};

/* Rotate array (in place) using 3 reverse operations */

k = k % n; // to account for cases where k > n

reverse(array, 0, array.length - 1);

reverse(array, 0, k - 1);

reverse(array, k, array.length - 1);

/* Print output */

for (int i = 0; i < array.length ; i++) {

System.out.println(array[i] +" ");

}

}

/* Reverses array from "start" to "end" inclusive */

private static void reverse(int [] array, int start, int end) {

if (array == null || start < 0 || start >= array.length ||

end < 0 || end >= array.length || start >= end) {

return;

}

int mid = (start + end) / 2;

for (int i = start; i <= mid; i++) {

int offset = i - start;

swap(array, start + offset, end - offset);

}

}

private static void swap (int [] array, int i, int j) {

int temp = array[i];

array[i] = array[j];

array[j] = temp;

}

}