Java/src/main/java/com/thealgorithms/bitmanipulation/BooleanAlgebraGates.java

package com.thealgorithms.bitmanipulation;

import java.util.List;

/**
 * Implements various Boolean algebra gates (AND, OR, NOT, XOR, NAND, NOR)
 */
public final class BooleanAlgebraGates {

    private BooleanAlgebraGates() {
        // Prevent instantiation
    }

    /**
     * Represents a Boolean gate that takes multiple inputs and returns a result.
     */
    interface BooleanGate {
        /**
         * Evaluates the gate with the given inputs.
         *
         * @param inputs The input values for the gate.
         * @return The result of the evaluation.
         */
        boolean evaluate(List<Boolean> inputs);
    }

    /**
     * AND Gate implementation.
     * Returns true if all inputs are true; otherwise, false.
     */
    static class ANDGate implements BooleanGate {
        @Override
        public boolean evaluate(List<Boolean> inputs) {
            for (boolean input : inputs) {
                if (!input) {
                    return false;
                }
            }
            return true;
        }
    }

    /**
     * OR Gate implementation.
     * Returns true if at least one input is true; otherwise, false.
     */
    static class ORGate implements BooleanGate {
        @Override
        public boolean evaluate(List<Boolean> inputs) {
            for (boolean input : inputs) {
                if (input) {
                    return true;
                }
            }
            return false;
        }
    }

    /**
     * NOT Gate implementation (Unary operation).
     * Negates a single input value.
     */
    static class NOTGate {
        /**
         * Evaluates the negation of the input.
         *
         * @param input The input value to be negated.
         * @return The negated value.
         */
        public boolean evaluate(boolean input) {
            return !input;
        }
    }

    /**
     * XOR Gate implementation.
     * Returns true if an odd number of inputs are true; otherwise, false.
     */
    static class XORGate implements BooleanGate {
        @Override
        public boolean evaluate(List<Boolean> inputs) {
            boolean result = false;
            for (boolean input : inputs) {
                result ^= input;
            }
            return result;
        }
    }

    /**
     * NAND Gate implementation.
     * Returns true if at least one input is false; otherwise, false.
     */
    static class NANDGate implements BooleanGate {
        @Override
        public boolean evaluate(List<Boolean> inputs) {
            return !new ANDGate().evaluate(inputs); // Equivalent to negation of AND
        }
    }

    /**
     * NOR Gate implementation.
     * Returns true if all inputs are false; otherwise, false.
     */
    static class NORGate implements BooleanGate {
        @Override
        public boolean evaluate(List<Boolean> inputs) {
            return !new ORGate().evaluate(inputs); // Equivalent to negation of OR
        }
    }
}