Algorithm to rotate an array in linear time

Question

How to rotate an integer array by i times using swap function only in linear time.

Answer 1

Simple Solution in O(n) time and using O(1) space:
for e.g 1,2,3,4,5,6,7
rotating 2 times 
start with index 2, store a[0] as last
Iteration 1: 1,2,1,4,3,6,5 (1-->3-->5-->7)
Iteration 2: 1,7,1,2,3,4,5 (2-->4-->6)
replace 1 with 6 (last value).

public int[] roatateArray(int[] a,int k)
{
    int last = a[0];
    int start = k;
    for(int j=0;j