Create Binary Search function

Binary Search function

+ int binarysearch(int arr[], int n, int k){
+        // code here
+        int low=0, high = n-1, mid;
+        while(low<=high)
+        {
+            mid = (low+high)/2;
+            
+            if(low==high)
+            {
+                if(arr[low]==k)
+                    return low;
+                else
+                    return -1;
+            }
+            else
+            {   
+                if(arr[mid]==k)
+                    return mid;
+                else
+                {
+                    if(arr[mid]<k)
+                        low = mid+1;
+                    else
+                        high = mid-1;
+                }
+            }
+        }
+        return -1;
+    }