test: add doctests and edge case coverage for binary search on answer implementation

Author: meenaksh06

searches/binary_search_on_answers.py

@@ -40,6 +40,34 @@ def binary_search_on_answer(
 
     return answer
 
+# Doctests-1. Doctests for binary_search_on_answer
+
+"""
+Generic Binary Search on Answer template.
+
+Finds the minimum value in the range [low, high] that satisfies the condition.
+
+The condition must be monotonic:
+False False False True True True
+
+Examples:
+>>> def condition(x): return x * x >= 16
+>>> binary_search_on_answer(0, 10, condition)
+4
+
+>>> def condition(x): return x >= 7
+>>> binary_search_on_answer(0, 10, condition)
+7
+
+>>> def condition(x): return x >= 0
+>>> binary_search_on_answer(-5, 5, condition)
+0
+
+>>> def condition(x): return True
+>>> binary_search_on_answer(1, 5, condition)
+1
+"""
+
 
 # Example1: minimum capacity to ship
 
@@ -63,4 +91,30 @@ def can_ship(capacity: int) -> bool:
 
         return days_used <= days
 
-    return binary_search_on_answer(max(weights), sum(weights), can_ship)
+    return binary_search_on_answer(max(weights), sum(weights), can_ship)
+
+# Doctest-2. Doctests for min_capacity_to_ship
+
+"""
+Find minimum capacity to ship packages within given days.
+
+Examples:
+>>> min_capacity_to_ship([1,2,3,4,5,6,7,8,9,10], 5)
+15
+
+>>> min_capacity_to_ship([3,2,2,4,1,4], 3)
+6
+
+>>> min_capacity_to_ship([1,2,3,1,1], 4)
+3
+
+>>> min_capacity_to_ship([10], 1)
+10
+"""
+
+# Edge case to be handled
+"""
+>>> def condition(x): return x >= 100
+>>> binary_search_on_answer(0, 50, condition)
+50
+"""