Generate random numbers using a quantum circuit.

Author: primaryobjects

hello.py

@@ -1,12 +1,12 @@
 import random
-from math import ceil, floor, log
-from lib.util import execute, generate
+from math import floor, log
+from lib.util import execute, num_qubits, random_letters
 from lib.grover import grover
 from lib.oracles.logic import oracle
 
 def init(target, n):
     # Initialize an array of random letters, including the target ones in the string.
-    arr = generate(n)
+    arr = random_letters(n)
 
     # Store used indices so that we don't overwrite target letters.
     indices = [-1]
@@ -87,7 +87,7 @@ def main(phrase):
     execute.provider = None
 
     # Calculate the number of qubits needed to represent the number of letters in the target.
-    qubits = ceil(log(len(phrase), 2))
+    qubits = num_qubits(len(phrase))
 
     bits = 2 ** qubits
     arr = init(phrase, bits)

lib/util.py

@@ -2,16 +2,57 @@
 import random
 import string
 import time
+from math import ceil, log
 from configparser import RawConfigParser
-from qiskit import qiskit, Aer, IBMQ
+from qiskit import qiskit, Aer, IBMQ, QuantumCircuit
 
-def generate(n):
+def random_letters(n):
     # Generate an array of random letters.
     letters = []
     for i in range(n):
         letters.append(random.choice(string.ascii_letters))
     return letters
 
+def random_number(minimum, maximum):
+    # Uses a quantum circuit to generate a random number from minimum (inclusive) to maximum (exclusive).
+    # Determine the number of qubits required.
+    n = num_qubits(maximum-1)
+
+    # Create a quantum circuit with enough qubits for the max value.
+    qc = QuantumCircuit(n)
+
+    # Place all qubits into superposition.
+    qc.h(range(n))
+
+    # Measure the result.
+    qc.measure_all()
+
+    # Continue executing the circuit until we obtain a value within range.
+    r = -1
+    count = 0
+    max_count = 10
+    while (r < minimum or r >= maximum) and count < max_count:
+        # Execute the circuit.
+        result = execute(qc)
+
+        # Get the resulting hit counts.
+        counts = result.get_counts()
+
+        # Find the most frequent hit count.
+        key = max(counts, key=counts.get)
+
+        # Since the quantum computer returns a binary string (one bit for each qubit), we need to convert it to an integer.
+        r = int(key, 2)
+
+        # Increment the count before we break.
+        count = count + 1
+
+    return r
+
+def num_qubits(i):
+    # Returns the number of qubits needed to represent the value i.
+    return ceil(log(i, 2))
+
 def execute(qc):
     # Setup the API key for the real quantum computer.
     parser = RawConfigParser()

magicball.py

@@ -1,6 +1,4 @@
-import random
-from math import ceil, log
-from lib.util import execute
+from lib.util import random_number, num_qubits, execute
 from lib.grover import grover
 from lib.oracles.numeric import oracle
 
@@ -47,10 +45,10 @@ def main():
     input('Please ask me a yes/no question and I will predict your future [PRESS ANY KEY] ...')
 
     # Determine the number of qubits required.
-    n = ceil(log(len(predictions), 2))
+    n = num_qubits(len(predictions))
 
-    # Select a random prediction.
-    r = random.choice(range(len(predictions)))
+    # Generate a random number using a quantum circuit.
+    r = random_number(0, len(predictions))
 
     print()
     print('Selected random index ' + str(r))