Expresiones.java

import java.util.Set;
import java.util.Stack;

public class Expresiones extends javax.swing.JFrame {

    public Expresiones() {
        initComponents();
    }

    @SuppressWarnings("unchecked")

    private void initComponents() {

        jLabel1 = new javax.swing.JLabel();
        txtExpresion = new javax.swing.JTextField();
        jLabel2 = new javax.swing.JLabel();
        jButton1 = new javax.swing.JButton();
        jLabel3 = new javax.swing.JLabel();
        lblTipoExp = new javax.swing.JLabel();
        jLabel4 = new javax.swing.JLabel();
        btnInfAPos = new javax.swing.JButton();
        btnInfAPref = new javax.swing.JButton();
        btnPosAPref = new javax.swing.JButton();
        btnPrefAPos = new javax.swing.JButton();
        btnPosAInf = new javax.swing.JButton();
        btnPrefAInf = new javax.swing.JButton();
        jLabel5 = new javax.swing.JLabel();
        txtConversion = new javax.swing.JTextField();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jLabel1.setFont(new java.awt.Font("Segoe UI", 0, 24)); // NOI18N
        jLabel1.setText("Bienvenido,");

        jLabel2.setFont(new java.awt.Font("Segoe UI", 0, 14)); // NOI18N
        jLabel2.setText("Ingrese la expresión:");

        jButton1.setText("Validar Expresión");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        jLabel3.setText("El tipo de expresion es :");

        lblTipoExp.setText("NULL");
        lblTipoExp.setEnabled(false);

        jLabel4.setFont(new java.awt.Font("Segoe UI", 0, 14)); // NOI18N
        jLabel4.setText("Seleccione la conversión a realizar:");
        jLabel4.setEnabled(false);

        btnInfAPos.setText("Infija a PosFija");
        btnInfAPos.setEnabled(false);
        btnInfAPos.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                btnInfAPosActionPerformed(evt);
            }
        });

        btnInfAPref.setText("Infija a Prefija");
        btnInfAPref.setEnabled(false);
        btnInfAPref.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                btnInfAPrefActionPerformed(evt);
            }
        });

        btnPosAPref.setText("PosFija a Prefija");
        btnPosAPref.setEnabled(false);

        btnPrefAPos.setText("Prefija A PosFija");
        btnPrefAPos.setEnabled(false);

        btnPosAInf.setText("PosFija a Infija");
        btnPosAInf.setEnabled(false);

        btnPrefAInf.setText("Prefija a Infija");
        btnPrefAInf.setEnabled(false);

        jLabel5.setFont(new java.awt.Font("Segoe UI", 0, 14)); // NOI18N
        jLabel5.setText("Expresión Convertida");
        jLabel5.setEnabled(false);

        txtConversion.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                txtConversionActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(jLabel1)
                        .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                        .addGap(0, 0, Short.MAX_VALUE)
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(jLabel2)
                            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
                                .addGroup(layout.createSequentialGroup()
                                    .addComponent(jLabel3)
                                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                                    .addComponent(lblTipoExp))
                                .addGroup(layout.createSequentialGroup()
                                    .addComponent(txtExpresion, javax.swing.GroupLayout.PREFERRED_SIZE, 200, javax.swing.GroupLayout.PREFERRED_SIZE)
                                    .addGap(20, 20, 20)
                                    .addComponent(jButton1))))
                        .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))))
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addComponent(jLabel4)
                .addGap(0, 0, Short.MAX_VALUE))
            .addGroup(layout.createSequentialGroup()
                .addGap(80, 80, 80)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                    .addComponent(btnInfAPos, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(btnInfAPref, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                .addGap(100, 100, 100)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                    .addComponent(btnPosAPref, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(btnPosAInf, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                .addGap(100, 100, 100)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                    .addComponent(btnPrefAPos, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(btnPrefAInf, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                .addGap(80, 80, 80))
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addComponent(jLabel5)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addComponent(txtConversion, javax.swing.GroupLayout.PREFERRED_SIZE, 200, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jLabel1)
                .addGap(39, 39, 39)
                .addComponent(jLabel2)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(txtExpresion, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jButton1))
                .addGap(18, 18, 18)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel3)
                    .addComponent(lblTipoExp))
                .addGap(60, 60, 60)
                .addComponent(jLabel4)
                .addGap(30, 30, 30)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(btnInfAPos)
                    .addComponent(btnPosAPref)
                    .addComponent(btnPrefAPos))
                .addGap(18, 18, 18)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(btnInfAPref)
                    .addComponent(btnPosAInf)
                    .addComponent(btnPrefAInf))
                .addGap(30, 30, 30)
                .addComponent(jLabel5)
                .addGap(18, 18, 18)
                .addComponent(txtConversion, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(39, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        

    private void btnInfAPrefActionPerformed(java.awt.event.ActionEvent evt) {                                            
        
    }                                           

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        String expresion = txtExpresion.getText().trim();
        String tipo = determinarTipoExpresion(expresion);

        if (tipo == null) {
            lblTipoExp.setEnabled(true);
            lblTipoExp.setText("Null");
            deshabilitarBotonesConversion();
            jLabel4.setEnabled(false);
        } else {
            lblTipoExp.setEnabled(true);
            lblTipoExp.setText(tipo);
            jLabel4.setEnabled(true);
            habilitarBotonesTipo(tipo);
        }
    }                                        

    private void btnInfAPosActionPerformed(java.awt.event.ActionEvent evt) {                                           
        String expresion = txtExpresion.getText().trim();
        if (expresion.isEmpty()) {
            txtConversion.setText("Error: La expresión no puede estar vacía.");
        } else {
            try {
                String resultado = convertirInfijoAPostfijo(expresion);
                txtConversion.setText("Expresión Postfija: " + resultado);
            } catch (Exception ex) {
                txtConversion.setText("Error en la expresión algebraica: " + ex.getMessage());
            }
        }
    }                                          

    private void txtConversionActionPerformed(java.awt.event.ActionEvent evt) {                                              
        // TODO add your handling code here:
    }                                             

    public static void main(String args[]) {
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(Expresiones.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Expresiones.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Expresiones.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Expresiones.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }

        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new Expresiones().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton btnInfAPos;
    private javax.swing.JButton btnInfAPref;
    private javax.swing.JButton btnPosAInf;
    private javax.swing.JButton btnPosAPref;
    private javax.swing.JButton btnPrefAInf;
    private javax.swing.JButton btnPrefAPos;
    private javax.swing.JButton jButton1;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JLabel jLabel5;
    private javax.swing.JLabel lblTipoExp;
    private javax.swing.JTextField txtConversion;
    private javax.swing.JTextField txtExpresion;
    // End of variables declaration                   

    private void habilitarBotonesTipo(String tipo) {
        deshabilitarBotonesConversion();
        switch (tipo) {
            case "Infija":
                btnInfAPref.setEnabled(true);
                btnInfAPos.setEnabled(true);
                break;
            case "Posfija":
                btnPosAPref.setEnabled(true);
                btnPosAInf.setEnabled(true);
                break;
            case "Prefija":
                btnPrefAPos.setEnabled(true);
                btnPrefAInf.setEnabled(true);
                break;
        }
    }

    private void deshabilitarBotonesConversion() {
        btnInfAPos.setEnabled(false);
        btnInfAPref.setEnabled(false);
        btnPosAPref.setEnabled(false);
        btnPrefAPos.setEnabled(false);
        btnPosAInf.setEnabled(false);
        btnPrefAInf.setEnabled(false);
    }

    private int pref(String op) {
        int prf = 99;
        if (op.equals("^")) {
            prf = 5;
        }
        if (op.equals("*") || op.equals("/")) {
            prf = 4;
        }
        if (op.equals("+") || op.equals("-")) {
            prf = 3;
        }
        if (op.equals(")")) {
            prf = 2;
        }
        if (op.equals("(")) {
            prf = 1;
        }
        return prf;
    }

    private String depurar(String s) {
        s = s.replaceAll("\\s+", ""); // Eliminar espacios
        s = "(" + s + ")"; // Añadir paréntesis para facilitar el análisis
        String simbols = "+-*/()^";
        StringBuilder str = new StringBuilder();

        for (int i = 0; i < s.length(); i++) {
            if (simbols.contains("" + s.charAt(i))) {
                str.append(" ").append(s.charAt(i)).append(" ");
            } else {
                str.append(s.charAt(i));
            }
        }

        return str.toString().replaceAll("\\s+", " ").trim();
    }

    private String convertirInfijoAPostfijo(String expr) {
        expr = depurar(expr); // Limpiar la expresión
        String[] arrayInfix = expr.split(" "); // Separar los tokens

        Stack<String> E = new Stack<>(); // Pila de entrada
        Stack<String> P = new Stack<>(); // Pila para operadores
        Stack<String> S = new Stack<>(); // Pila de salida

        // Llenar la pila de entrada
        for (String token : arrayInfix) {
            E.push(token);
        }

        // Procesar la expresión
        while (!E.isEmpty()) {
            String current = E.pop();
            int precedence = pref(current); // Obtener la precedencia del operador

            if (current.equals("(")) {
                P.push(current);
            } else if (current.equals(")")) {
                while (!P.isEmpty() && !P.peek().equals("(")) {
                    S.push(P.pop());
                }
                P.pop(); // Eliminar el '('
            } else if (precedence >= 3) { // Operadores de alta precedencia
                while (!P.isEmpty() && pref(P.peek()) >= precedence) {
                    S.push(P.pop());
                }
                P.push(current);
            } else {
                S.push(current);
            }
        }

        // Mover lo que queda en la pila de operadores a la pila de salida
        while (!P.isEmpty()) {
            S.push(P.pop());
        }

        // Convertir la pila de salida a cadena
        StringBuilder result = new StringBuilder();
        while (!S.isEmpty()) {
            result.insert(0, S.pop() + " "); // Insertar al inicio para preservar el orden
        }

        return result.toString().trim(); // Limpiar los espacios extra
        }

        public String determinarTipoExpresion(String expresion) {
            // Eliminar espacios iniciales y finales
            expresion = expresion.trim();
    
            // Asegurarnos de que los tokens estén separados por espacios
            expresion = depurar(expresion);
            String[] tokens = expresion.split("\\s+");
    
            // Validar paréntesis balanceados
            if (!parentesisBalanceados(tokens)) {
                return "Error: Paréntesis desbalanceados";
            }
    
            // Validar estructura correcta
            if (!estructuraValida(tokens)) {
                return "Error: Estructura inválida";
            }
    
            // Validar si es prefija: el primer token debe ser operador
            if (tokens.length > 1 && esOperador(tokens[0]) && !esOperador(tokens[1])) {
                return "Prefija";
            }
    
            // Validar si es posfija: el último token debe ser operador
            if (tokens.length > 1 && esOperador(tokens[tokens.length - 1]) && !esOperador(tokens[tokens.length - 2])) {
                return "Posfija";
            }
    
            // Validar si es infija: los operadores deben estar entre operandos
            boolean esInfija = true;
            for (int i = 1; i < tokens.length - 1; i++) {
                if (esOperador(tokens[i]) && (esOperador(tokens[i - 1]) || esOperador(tokens[i + 1]))) {
                    esInfija = false;
                    break;
                }
            }
            if (esInfija) {
                return "Infija";
            }
    
            // Si no coincide con ninguna, retornamos desconocida
            return "Error: Tipo de expresión desconocido";
        }
    
        private boolean esOperador(String token) {
        return token.matches("[+\\-*/^()]");
        }
        

    private boolean parentesisBalanceados(String[] tokens) {
        Stack<String> pila = new Stack<>();
        for (String token : tokens) {
            if (token.equals("(")) {
                pila.push(token);
            } else if (token.equals(")")) {
                if (pila.isEmpty()) {
                    return false; // Paréntesis de cierre sin apertura
                }
                pila.pop();
            }
        }
        return pila.isEmpty(); // Si la pila no está vacía, hay paréntesis de apertura sin cerrar
    }

    private boolean estructuraValida(String[] tokens) {
        for (int i = 0; i < tokens.length; i++) {
            String token = tokens[i];

            // Verificar que no haya dos operadores consecutivos
            if (esOperador(token) && (i == 0 || esOperador(tokens[i - 1]))) {
                return false;
            }

            // Verificar que los operadores no estén al final
            if (esOperador(token) && i == tokens.length - 1) {
                return false;
            }

            // Verificar que no haya paréntesis de apertura o cierre mal colocados
            if ((token.equals("(") || token.equals(")")) && (i == 0 || i == tokens.length - 1)) {
                return false;
            }
        }
        return true;
    }

}