From 4e69938d7b55a8f1b50bd263e10247504b91b158 Mon Sep 17 00:00:00 2001
From: Daniel Tsvetkov <danieltcv@gmail.com>
Date: Mon, 9 Mar 2020 09:42:55 +0100
Subject: [PATCH] 3sat and grover fixes

---
 3sat.py   |  4 ++--
 grover.py | 19 +++++++++++++++++--
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/3sat.py b/3sat.py
index c979092..d39d56f 100644
--- a/3sat.py
+++ b/3sat.py
@@ -3,7 +3,7 @@ import itertools
 import random
 from pprint import pprint
 
-from grover import classical_func_search
+from grover import classical_func_search_multi_rv
 
 
 class X(object):
@@ -88,7 +88,7 @@ def classical_3sat(func):
     # Generate all possible true/false tupples for the 3-sat problem
     input_range = list(itertools.product([True, False], repeat=func.predicates))
     random.shuffle(input_range)
-    return classical_func_search(func, input_range)
+    return classical_func_search_multi_rv(func, input_range)
 
 
 def main():
diff --git a/grover.py b/grover.py
index 01401ae..986ffe4 100644
--- a/grover.py
+++ b/grover.py
@@ -4,7 +4,7 @@ import random
 from pprint import pprint
 
 
-def classical_func_search(func, input_range):
+def classical_func_search_multi_rv(func, input_range):
     """Grover’s algorithm takes a function, searches through
     the implicit list of possible inputs to that function, and
     returns inputs that causes the function to return true.
@@ -17,6 +17,21 @@ def classical_func_search(func, input_range):
     return rv
 
 
+def classical_func_search_single_rv(func, input_range):
+    """Grover’s algorithm takes a function, searches through
+    the implicit list of possible inputs to that function, and
+    returns EXACTLY ONE input that causes the function to return true.
+    """
+    rv = None
+    for i, params in enumerate(input_range):
+        result = func(params)
+        if result and rv is None:
+            rv = result
+        else:
+            raise Exception("Exactly one result is needed")
+    return rv
+
+
 def _3sat(params):
     # https://cstheory.stackexchange.com/questions/38538/oracle-construction-for-grovers-algorithm
     # 3-SAT from here: https://qiskit.org/textbook/ch-applications/satisfiability-grover.html
@@ -32,7 +47,7 @@ def classical_3sat(func):
     # Generate all possible true/false tupples for the 3-sat problem
     input_range = list(itertools.product([True, False], repeat=3))
     random.shuffle(input_range)
-    return classical_func_search(func, input_range)
+    return classical_func_search_multi_rv(func, input_range)
 
 
 def main():