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

void reverse_array(int a[], int start, int end){

    while(start < end){     
            int temp =  a[start];
            a[start] = a[end];
            a[end] = temp;
            start++;
            end--;
    }

}

void rotate_array(int a[], int pivot, int len){
    int i;
    /*Reverse the whole array */
    reverse_array(a, 0, len);

    /* Reverse from 0 to pivot and pivot to end */
    reverse_array(a,0, pivot);
    reverse_array(a,pivot+1,len);

}