binary search on a circularly shifted array

A sorted array is shifted circularly (i.e m elements from start are removed from start and added to the end). Now write an algorithm to search for an element.

public static int bS(int[] a, int left, int right, int key) {

while (left <= right) {

int mid = left + (right - left) / 2;

if (a[mid] == key)

return mid;

if (a[left] > a[mid]) {

// switching has happened in left partition

// if key is less than the mid, sure it is in left partition

if (key > a[mid] && key <>

// then RP

left = mid + 1;

else

// LP

right = mid - 1; // for 2 cases, one is : if key <>

} else if (a[right] <>

// partition

if (key <> a[right])

// then LP

right = mid - 1;

else

// RP

left = mid + 1; // 2 cases, one is : if key > a[mid]just

} else

// following 2 are cases where there is no switching at all

if (key <>

// LP

right = mid - 1;

else

// RP

left = mid + 1;

}

return -1;

}