Test cases for bisect_left and bisect_right

utilities/python/binary_search.py

@@ -46,3 +46,24 @@ print(binary_search([1, 2, 3, 10], 4) == -1)
 print(binary_search([1, 2, 3, 10], 0) == -1)
 print(binary_search([1, 2, 3, 10], 11) == -1)
 print(binary_search([5, 7, 8, 10], 3) == -1)
+
+print(bisect_left([1, 2, 3, 3, 10], 1) == 0)
+print(bisect_left([1, 2, 3, 3, 10], 2) == 1)
+print(bisect_left([1, 2, 3, 3, 10], 3) == 2) # First "3" is at index 2
+print(bisect_left([1, 2, 3, 3, 10], 10) == 4)
+
+# These return a valid index despite target not being in array.
+print(bisect_left([1, 2, 3, 3, 10], 9) == 4)
+print(bisect_left([1, 2, 3, 3, 10], 0) == 0) # Insert "0" at front
+print(bisect_left([1, 2, 3, 3, 10], 11) == 5) # Insert "5" at back
+
+print(bisect_right([1, 2, 3, 3, 10], 1) == 1)
+print(bisect_right([1, 2, 3, 3, 10], 2) == 2)
+print(bisect_right([1, 2, 3, 3, 10], 3) == 4) # Last "3" is at index 3, so insert new "3" at index 4
+print(bisect_right([1, 2, 3, 3, 10], 10) == 5)
+
+# These return a valid index despite target not being in array.
+print(bisect_right([1, 2, 3, 3, 10], 9) == 4)
+print(bisect_right([1, 2, 3, 3, 10], 0) == 0) # Insert "0" at front
+print(bisect_right([1, 2, 3, 3, 10], 11) == 5) # Insert "5" at back
+