Respuestas de los ejercicios de los examenes

Ejercicio2.java

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package examenI;
import java.util.Scanner;
/**
 *
 * @author dturcios
 */
public class Ejercicio2 {
    public static void main(String[] args) {
        Scanner leer = new Scanner(System.in);
        System.out.print("Ingrese un numero: ");
        int num1 = leer.nextInt();
        System.out.print("Ingrese otro numero: ");
        int num2 = leer.nextInt();
        System.out.println("La respuesta es: "+ num1+ num2);
    }
    
}

Ejercicio3.java

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package examenI;
import java.util.Scanner;
/**
 *
 * @author dturcios
 */
public class Ejercicio3 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int opcion =0;
        String oneword = "";
        String copyword;
        do{
            System.out.println("Palindromo");
            System.out.println("1) Es palindromo?");
            System.out.println("2) Salir");
            opcion = sc.nextInt();
            
            switch(opcion){
                case 1:
                    System.out.println("Palindromo");
                    System.out.println("Ingrese la palabra para saber si palindromo: ");
                    oneword = sc.next();
                    System.out.println("Usando arrays");
                    char []onewordArray = oneword.toCharArray();
                    for(int i=0;i<(onewordArray.length-1)/2;i++){
                        char temp = onewordArray[i];
                        onewordArray[i] = onewordArray[onewordArray.length-1];
                        onewordArray[onewordArray.length-1] = temp;
                    }
                    copyword = new String(onewordArray);
                    if(oneword.equals(copyword)){
                        System.out.println("La palabra "+ oneword + " si es palindromo");
                    }
                    else{
                        System.out.println("La palabra "+ oneword + " No es palindromo");                        
                    }
                    System.out.println("Usando el string");
                    String secondword="";
                    for(int i=oneword.length()-1; i>=0 ;i--){
                        secondword = secondword + oneword.charAt(i);
                    }
                    if(secondword.equals(oneword)){
                        System.out.println("La palabra "+ oneword + " si es palindromo");
                    }
                    else{
                        System.out.println("La palabra "+ oneword + " No es palindromo");                        
                    }
            }
        }while(opcion!=2);
        
    }
}

Ejercicio4.java

package examenI;

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/**
 *
 * @author dturcios
 */
public class Ejercicio4 {
    public static void main(String[] args) {
        for(int i=5;i>0;i--){
            for(int j=0;j<i;j++){
                System.out.print("*");
            }
            System.out.println();
        }
    }
}

Ejercicio5.java

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package examenI;
import java.util.Scanner;


/**
 *
 * @author dturcios
 */
public class Ejercicio5 {
    public static void main(String[] args) {
        Scanner leer = new Scanner(System.in);
        int opcion =0;
        do{
            System.out.println("Menu");
            System.out.println("1) Tirar dado");
            System.out.println("2) Salir");
            System.out.print("Ingrese opcion: ");
            opcion = leer.nextInt();
            switch(opcion){
                case 1:
                System.out.println("Se va a lanzar el dado:");
                System.out.println("El numero que se lanzo fue: "+ (1+(int)(Math.random()*(6-1)+1)));
                System.out.println("El numero que se lanzo fue: "+ ((int)(Math.random()*6)));
                break;
                case 2:
                    break;
                default:
                    System.out.println("Ingrese una opcion valida");
            }
                    
            
        }while (opcion!=2);
    }
}