Rock paper scissors quantum computing qiskit using 1 qubit

rps.py

# Import Qiskit and numpy
from qiskit import QuantumCircuit, QuantumRegister, ClassicalRegister, execute, Aer
import numpy as np

# Define the quantum register and the classical register
qreg = QuantumRegister(1)
creg = ClassicalRegister(1)
qc = QuantumCircuit(qreg, creg)

# Define the basis states for rock, paper, and scissors
rock = [1, 0]
paper = [0, 1]
scissors = [1/np.sqrt(2), 1/np.sqrt(2)]

# Define the dictionary for the moves and their outcomes
moves = {
    'rock': {
        'state': rock,
        'beats': 'scissors',
        'losesTo': 'paper'
    },
    'paper': {
        'state': paper,
        'beats': 'rock',
        'losesTo': 'scissors'
    },
    'scissors': {
        'state': scissors,
        'beats': 'paper',
        'losesTo': 'rock'
    }
}

# Ask the user to enter their choice
user_choice = input("Enter a choice (rock, paper, scissors): ").lower()

# Validate the user input
while user_choice not in moves.keys():
    user_choice = input("Invalid choice. Must be rock, paper, or scissors: ").lower()

# Print the user choice
print(f"You chose {user_choice}.")

# Initialize the qubit with the user choice state
qc.initialize(moves[user_choice]['state'], 0)

# Apply a Hadamard gate to the qubit to create a superposition of 0 and 1
qc.h(0)

# Measure the qubit
qc.measure(qreg, creg)

# Print the circuit
print(qc)

# Execute the circuit on the Qasm simulator
simulator = Aer.get_backend('qasm_simulator')
result = execute(qc, simulator, shots=1).result()

# Get the counts of the outcomes
counts = result.get_counts(qc)

# Get the binary string of the outcome
outcome = list(counts.keys())[0]

# Get the first bit of the outcome binary string
outcome_bit = outcome[0]

# Get the computer choice from the outcome bit value
computer_choice = list(moves.keys())[int(outcome_bit)]

# Print the computer choice
print(f"The computer chose {computer_choice}.")

# Compare the user choice and the computer choice to determine the winner
if user_choice == computer_choice:
    print("It's a tie.")
elif moves[user_choice]['beats'] == computer_choice:
    print("You win!")
else:
    print("You lose.")

rps2.py

from qiskit import QuantumCircuit, QuantumRegister, ClassicalRegister, execute, Aer
import numpy as np

# Define the quantum register and the classical register
qreg = QuantumRegister(2)
creg = ClassicalRegister(2)

# Define the basis states for rock, paper, and scissors
rock = [1, 0, 0, 0]
paper = [0, 1, 0, 0]
scissors = [1/np.sqrt(2), 0, 1/np.sqrt(2), 0]

# Define the dictionary for the moves and their outcomes
moves = {
    'rock': {
        'state': rock,
        'beats': 'scissors',
        'losesTo': 'paper',
        'shortcut': 'r'
    },
    'paper': {
        'state': paper,
        'beats': 'rock',
        'losesTo': 'scissors',
        'shortcut': 'p'
    },
    'scissors': {
        'state': scissors,
        'beats': 'paper',
        'losesTo': 'rock',
        'shortcut': 's'
    },
    'quit': {
        'shortcut': 'q'
    }
}

user_choice = ''
while user_choice != 'quit':
    # Ask the user to enter their choice
    user_choice = input("Enter a choice (rock, paper, scissors, quit): ").lower()

    # Check if the user entered a shortcut and convert it to the corresponding move
    for move in moves:
        if user_choice == moves[move]['shortcut']:
            user_choice = move
            break

    # Validate the user input
    while user_choice not in moves.keys():
        user_choice = input("Invalid choice. Must be rock, paper, or scissors: ").lower()

        # Check if the user entered a shortcut and convert it to the corresponding move
        for move in moves:
            if user_choice == moves[move]['shortcut']:
                user_choice = move
                break

    if user_choice == 'quit':
        break

    # Print the user choice
    print(f"You chose {user_choice}.")

    qc = QuantumCircuit(qreg, creg)

    # Initialize the qubits with the user choice state
    qc.initialize(moves[user_choice]['state'], [0, 1])

    # Apply a Hadamard gate to the first qubit to create a superposition of 0 and 1
    qc.h(0)

    # Measure the qubits
    qc.measure(qreg, creg)

    # Print the circuit
    print(qc)

    # Execute the circuit on the Qasm simulator
    simulator = Aer.get_backend('qasm_simulator')
    result = execute(qc, simulator, shots=1).result()

    # Get the counts of the outcomes
    counts = result.get_counts(qc)

    # Get the binary string of the outcome
    outcome = list(counts.keys())[0]
    print(outcome)

    # Get the right-most bit of the outcome binary string
    outcome_bit = outcome

    # Handle invalid move.
    if outcome_bit == '11':
        outcome_bit = '10'

    # Get the computer choice from the outcome bit value
    computer_choice = list(moves.keys())[int(outcome_bit, 2)]

    # Print the computer choice
    print(f"The computer chose {computer_choice}.")

    # Compare the user choice and the computer choice to determine the winner
    if user_choice == computer_choice:
        print("It's a tie.")
    elif moves[user_choice]['beats'] == computer_choice:
        print("You win!")
    else:
        print("You lose.")

rps3.py

# Import Qiskit and numpy
from qiskit import QuantumCircuit, QuantumRegister, ClassicalRegister, execute, Aer
import numpy as np

# Define the quantum registers and the classical registers
qreg = QuantumRegister(2)
creg = ClassicalRegister(2)
qc = QuantumCircuit(qreg, creg)

# Define the basis states for rock, paper, and scissors
rock = [1, 0]
paper = [0, 1]
scissors = [1/np.sqrt(2), 1/np.sqrt(2)]

# Define the dictionary for the moves and their outcomes
moves = {
    'rock': {
        'state': rock,
        'beats': 'scissors',
        'losesTo': 'paper'
    },
    'paper': {
        'state': paper,
        'beats': 'rock',
        'losesTo': 'scissors'
    },
    'scissors': {
        'state': scissors,
        'beats': 'paper',
        'losesTo': 'rock'
    }
}

# Ask the user to enter their choice
user_choice = input("Enter a choice (rock, paper, scissors): ").lower()

# Validate the user input
while user_choice not in moves.keys():
    user_choice = input("Invalid choice. Must be rock, paper, or scissors: ").lower()

# Print the user choice
print(f"You chose {user_choice}.")

# Initialize the first qubit with the user choice state
qc.initialize(moves[user_choice]['state'], 0)

# Apply a Hadamard gate to the second qubit to create a superposition of 0 and 1
qc.h(1)

# Apply a CNOT gate to both qubits to entangle them
qc.cx(0, 1)

# Measure the qubits
qc.measure(qreg, creg)

# Execute the circuit on the Qasm simulator
simulator = Aer.get_backend('qasm_simulator')
result = execute(qc, simulator, shots=1).result()

# Get the counts of the outcomes
counts = result.get_counts(qc)

# Get the binary string of the outcome
outcome = list(counts.keys())[0]

# Get the decimal value of the outcome
outcome_decimal = int(outcome, 2)

# Get the computer choice from the outcome decimal value
computer_choice = list(moves.keys())[outcome_decimal]

# Print the computer choice
print(f"The computer chose {computer_choice}.")

# Compare the user choice and the computer choice to determine the winner
if user_choice == computer_choice:
    print("It's a tie.")
elif moves[user_choice]['beats'] == computer_choice:
    print("You win!")
else:
    print("You lose.")

zoutput.txt

Enter a choice (rock, paper, scissors, quit): s
You chose scissors.
      ┌──────────────────────────────────┐┌───┐┌─┐
q0_0: ┤0                                 ├┤ H ├┤M├
      │  Initialize(0.70711,0,0.70711,0) │└┬─┬┘└╥┘
q0_1: ┤1                                 ├─┤M├──╫─
      └──────────────────────────────────┘ └╥┘  ║
c0: 2/══════════════════════════════════════╩═══╩═
                                            1   0
00
The computer chose rock.
You lose.


Enter a choice (rock, paper, scissors, quit): s
You chose scissors.
      ┌──────────────────────────────────┐┌───┐┌─┐
q0_0: ┤0                                 ├┤ H ├┤M├
      │  Initialize(0.70711,0,0.70711,0) │└┬─┬┘└╥┘
q0_1: ┤1                                 ├─┤M├──╫─
      └──────────────────────────────────┘ └╥┘  ║
c0: 2/══════════════════════════════════════╩═══╩═
                                            1   0
10
The computer chose scissors.
It's a tie.


Enter a choice (rock, paper, scissors, quit): q