int BinarySearch(int arr[], int len, int target) {
int first = 0;
int last = len-1;
int mid;
while ((first < last) && (arr[mid]!=target)) 
{
	// Assert: Array is sorted and first <= last
	//Initialization:target is within (extremes inclusive) the range of first and last. IE First<=x<=Last
	mid = (first+last) / 2;
	printf("mid: %d \n",mid);
	//Maintenance: Increasing first to mid+1 if x>mid or decrease last to min-1 if x<mid.
	if (target < arr[mid]) 
		{last = mid-1;
		printf("last: %d \n",last);
		}
	else 
		{first = mid+1;
		printf("first: %d \n",first);
		}
	}
//Termination: target is not within the array.
if ((first==last) && (arr[first]==target)) return 1;
	else return -1;
 
}
 
int main(){
int arr[10]={1,2,3,4,5,6,7,8,9,10};
int target=5;
int len=10;
 
printf("%d \n",BinarySearch( arr, len, target));
}

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