I did it as follows :
int arr[]= {1,2,5,5,5,6,8,9,10}; , number =5;
find first occurence and last occurence of given `number`
helper_rec(arr, number, firstindex , lastindex){
int mid = firstindex + lastindex/2;
if(arr[mid] == number){
int tempmid=mid;
while(arr[tempmid]==number && mid >=0){
tempmid--;
}
if(arr[tempmid+1]==number{
first = arr[tempmid+1];
}
tempmid =mid;
while(arr[tempmid]==number && mid< arr.length){
tempmid++;
}
if(arr[tempmid]==number){
second =arr[tempmid-1];
}
return;
}
if(mid< number ){
helper_rec(arr, number, mid+1, lastindex);
}
else{
helper_rec(arr, number , 0 , mid);
}
return;
}