The document contains 21 code examples that demonstrate sequential program structure in Java. Each example solves a different problem by prompting the user for input, performing calculations or logical operations, and displaying output. The examples cover basic math operations, conditional logic, string manipulation and other common programming tasks.

1. ESTRUCTURA SECUENCIAL
1°
/*
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*/
package problema.nº2;
import java.io.*;
/**
*
* @author ERIKA */
public class ProblemaNº1 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
int n1,n2,s;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("numero 1:");
n1 = Integer.parseInt(in.readLine());
System.out.println("numero 2:");
n2 = Integer.parseInt(in.readLine());
s=n1+n2;
System.out.println("");
System.out.println("suma: " +s);
}
}

2. 2°
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package problema3;
import java.io.*;
/**
*
* @author ERIKA
*/
public class Problema2 {
/**
* @param args the command line arguments
*/
public static void main(String[] args)throws IOException {
//varible
int n1,n2,c,r;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("numero 1:");
n1 = Integer.parseInt(in.readLine());
System.out.println("numero 2:");
n2 = Integer.parseInt(in.readLine());
//proceso
c=n1/n2;
r=n1%n2;
//salida
System.out.println("");
System.out.println("cociente: " +c);
System.out.println("residuo: " +r);
// TODO code application logic here
}
}

3. 3°
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package problema.pkg4;
import java.io.*;
/**
*
* @author ERIKA
*/
public class Problema3 {
/**
* @param args the command line arguments
*/
public static void main(String[] args)throws IOException {
//variable
float vv,igv,pv;
//entrada
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("valor de venta:");
vv =Float.parseFloat(in.readLine());
//proceso
igv = vv *0.18f;
pv = vv+ igv;
//salida
System.out.println("");
System.out.println("igv: " +igv);
System.out.println("precio de venta: " +pv);
// TODO code application logic here
}
}

4. 4°
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package problema04;
import java.io.*;
/**
*
* @author ERIKA
*/
public class PROBLEMA04 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
short n,r;
int a;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("a: ");
a=Integer.parseInt(in.readLine());
System.out.println("n: ");
n=Short.parseShort(in.readLine());
// TODO code application logic here
r=(short)Math.pow((double)a, (1/(double)n));
System.out.println("");
System.out.println("Radicación: "+r);
// TODO code application logic here
}
}

5. 5°
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package problema05;
import java.io.*;
/**
*
* @author ERIKA
*/
public class PROBLEMA05 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
short n,r;
int a;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("a: ");
a=Integer.parseInt(in.readLine());
System.out.println("n: ");
n=Short.parseShort(in.readLine());
// TODO code application logic here
r=(short)Math.pow((double)a, (1/(double)n));
System.out.println("");
System.out.println("Radicación: "+r);
// TODO code application logic here
}
}

6. 6°
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package problema06;
import java.io.*;
/**
*
* @author RODRIGO
*/
public class PROBLEMA06 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
// TODO code application logic here
int n, ni, r;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Número: ");
n=Integer.parseInt(in.readLine());
r=n%10;
n=n/10;
ni=r*10;
r=n%10;
n=n/10;
ni=(ni+r)*10;
r=n%10;
n=n/10;
ni=(ni+r)*10;
r=n%10;
n=n/10;
ni=(ni+r)*10;
ni=ni+n;
System.out.println("");
System.out.println("Inverso: " + ni);
}
}

7. 7°
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package problema07;
import java.io.*;
/**
*
* @author ERIKA
*/
public class PROBLEMA07 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
// TODO code application logic here
int n,s;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Número: ");
n=Integer.parseInt(in.readLine());
s=(n*(n+1))/2;
System.out.println("");
System.out.println("Suma: " + s);
}
}

8. 8°
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package problema8;
import java.io.*;
/**
*
* @author ERIKA
*/
public class Problema8 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
float c, r, t, i, m;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Capital: ");
c=Float.parseFloat(in.readLine());
System.out.println("Tasa de interes: ");
r=Float.parseFloat(in.readLine());
System.out.println("Tiempo: ");
t=Float.parseFloat(in.readLine());
m=(float)(Math.pow((double)(1+r/100),(double)t))*c;
i=m-c;
System.out.println("");
System.out.println("Interes: " + i);
System.out.println("Monto: " + m);
}
}

9. 9°
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package problema9;
import java.io.*;
/**
*
* @author ERIKA
*/
public class Problema9 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
// TODO code application logic here
//const float PI = 3.14159F;
final float PI=3.14159f;
float a,r;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Radio: ");
r=Float.parseFloat(in.readLine());
a=(float)(PI*(Math.pow((double)r, 2.0)));
System.out.println("");
System.out.println("Área: "+a);
}
}

10. 10°
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package problema10;
import java.io.*;
/**
*
* @author ERIKA
*/
public class Problema10 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
final int HORA=3600;
final int MINUTO=60;
int t,h,m,s;
BufferedReader in =new BufferedReader(new InputStreamReader(System.in));
System.out.println("Tiempo en segundos: ");
t=Integer.parseInt(in.readLine());
h=t/HORA;
//t=t%HORA;
m=t/MINUTO;
s=t;
System.out.println("");
System.out.println("Horas: "+h);
System.out.println("Minutos: "+m);
System.out.println("Segundos: "+s);
// TODO code application logic here
}
}

11. 11°
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package problema11;
import java.io.*;
/**
*
* @author ERIKA
*/
public class Problema11 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
int a,b,n1,n2;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Número1: ");
a=Integer.parseInt(in.readLine());
System.out.println("Número2: ");
b=Integer.parseInt(in.readLine());
n1=a+b;
n2=a-b;
System.out.println("");
System.out.println("Suma: " + n1);
System.out.println("Resta: " + n2);
// TODO code application logic here
}
}

12. 12°
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package problema012;
import java.io.*;
/**
*
* @author ERIKA
*/
public class Problema012 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException{
int n;
String r = "";
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Número: ");
n=(int)Integer.parseInt(in.readLine());
if (n>0)
{
r="POSITIVO";
}
if (n<0)
{
r="NEGATIVO";
}
if(n==0)
{
r="NEUTRO";
}
System.out.println("");
System.out.println("Resultado: "+r);
}
}

13. 13°
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package problema013;
import java.util.Scanner;
/**
*
* @author ERIKA
*/
public class Problema013 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
char c;
//String r="";
System.out.println("Caracter");
Scanner teclado=new Scanner(System.in);
c=teclado.next().charAt(0);
if(c=='a'||c=='e'||c=='i'||c=='o'||c=='u'||c=='A'||c=='E'||c=='I'||c=='O'
||c=='U'){
//r="es vocal";}
System.out.println("ES VOCAL");
} else{
//r="no es vocal"; }
System.out.println("NO ES VOCAL");
}//System.out.println("la letra ingresada "+r);
}
}

14. 14°
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package problema014;
import java.io.*;
/**
*
* @author ERIKA
*/
public class Problema014 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
int n;
String r;
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Numero: ");
n=Integer.parseInt(in.readLine());
if(n%3==0 && n%5==0)
{
r="SÍ ES MÚLTIPLO DE 3 Y 5";
}
else
{
r="NO ES MÚLTIPLO DE 3 Y 5";
}
System.out.println("");
System.out.println("Resultado:" + r);
System.out.println();
}
}

15. 15°
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package problema015;
import java.io.*;
/**
*
* @author ERIKA
*/
public class PROBLEMA015 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException{
// TODO code application logic here
int n;
String r;
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Número: ");
n=Integer.parseInt(in.readLine());
if(n%2==0)
{
r= "PAR";
}
else
{
r= "IMPAR";
}
System.out.println("");
System.out.println("Resultado: " + r);
System.out.println();
}
}

16. 16°
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package problema016;
import java.io.*;
/**
*
* @author ERIKA
*/
public class PROBLEMA016 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException{
int n1,n2,n3,m;
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Número 1: ");
n1= Integer.parseInt(in.readLine());
System.out.println("Número 2: ");
n2=Integer.parseInt(in.readLine());
System.out.println("Número 3: ");
n3= Integer.parseInt(in.readLine());
if (n1>n2)
{
if(n1>n3)
{
m=n1;
}
else
{
m=n3;
}
}
else
{
if(n2>n3)
{
m=n2;
}
else
{
m=n3;
}
}
System.out.println("");
System.out.println("Mayor: " +m);
}
}

17. 17°
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package problema017;
import java.io.*;
/**
*
* @author ERIKA
*/
public class PROBLEMA017 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException{
int n,r;
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Número: ");
n = Integer.parseInt(in.readLine());
if (!(n%2==0))
{
r=n*2;
}
else
{
r=n*3;
}
System.out.println("");
System.out.println("Resultado: " + r);
System.out.println();
}
}

18. 18°
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package problema018;
import java.io.*;
/**
*
* @author ERIKA
*/
public class PROBLEMA018 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException{
int n1, n2, n3, mayor, inter, menor;
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Número 1: ");
n1= Integer.parseInt(in.readLine());
System.out.println("Número 2: ");
n2=Integer.parseInt(in.readLine());
System.out.println("Número 3: ");
n3= Integer.parseInt(in.readLine());
if(n1 > n2 && n1 > n3)
{
mayor=n1;
}
else
{
if (n2 > n1 && n2> n3)
{
mayor=n2;
}
else
{
mayor=n3;
}
}
if(n1 < n2 && n1 < n3)
{
menor=n1;
}
else
{
if (n2 < n1 && n2 < n3)
{
menor=n2;
}
else
{
menor=n3;
}
}
inter=(n1 + n2 + n3)- (mayor + menor);

19. System.out.println("");
System.out.println("Mayor:" + mayor);
System.out.println("Inter:" + inter);
System.out.println("Menor:" + menor);
System.out.println();
}
}
19°
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package problema019;
import java.io.*;
/**
*
* @author ERIKA
*/
public class Problema019 {
/**
* @param args the command line arguments
*/
public static void main(String[] args)throws IOException{
final float D1=0.1F;
final float D2=0.2F;
final float IGV=0.18F;
float c,m_d, m_igv, p;
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Consumo: ");
c=(float)Integer.parseInt(in.readLine());
if(c<=100)
{
m_d=c * D1;
}
else
{
m_d=c * D2;
}
m_igv=(c-m_d) * IGV;
p= c - m_d + m_igv;
System.out.println("");
System.out.println("Monto descuento: " + m_d);
System.out.println("Impuesto IGV: " + m_igv);
System.out.println("Importe a pagar: " + p);
System.out.println();
}
}

20. 20°
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package problema020;
import java.io.*;
/**
*
* @author ERIKA
*/
public class Problema020 {
/**
* @param args the command line arguments
*/
public static void main(String[] args)throws IOException{
final float D1 = 0.1F;
final float D2 = 0.2F;
final float D3 = 0.3F;
final float IGV = 0.18F;
float c, m_d, m_igv, p;
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Consumo: ");
c=(float)Integer.parseInt(in.readLine());
if(c>200)
{
m_d=c*D3;
}
else
{
if(c>100)
{
m_d=c*D2;
}
else
{
m_d=c*D1;
}
}
m_igv=(c-m_d) * IGV;
p=c-m_d+m_igv;
System.out.println("");
System.out.println("Monto descuento: " + m_d);
System.out.println("Impuesto IGV: " + m_igv);
System.out.println("Importe a pagar: " + p);
System.out.println();
}
}

21. 21°
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package problema021;
import java.io.*;
/**
*
* @author ERIKA
*/
public class Problema021 {
/**
* @param args the command line arguments
*/
public static void main(String[] args)throws IOException{
int t;
String c;
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Temperatura: ");
t = Integer.parseInt(in.readLine());
if (t<10)
{
c="FRIO";
}
else
{
if (t>9 && t<21)
{
c="NUBLADO";
}
else
{
if (t>=21 && t<=30)
{
c="CALOR";
}
else
{
c="TROPICAL";
}
}
}
System.out.println("");
System.out.println("Clima: " + c);
System.out.println();
}
}

22. 22°
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*/
package problema022;
import java.util.Scanner;
/**
*
* @author ERIKA
*/
public class Problema022 {
/**
* @param args the command line arguments
*/
public static void main(String[] args){
Scanner in =new Scanner(System.in);
final float DESC_G = 0.15F;
final float DESC_A = 0.2F;
final float REC_G = 0.1F;
final float REC_A = 0.05F;
//variables
float mc, m, tp;
//char tc,fp;
String r ;
String tc;
String fp;
System.out.println("Monto de compra: ");
mc=in.nextFloat();
System.out.println("Tipo de cliente: ");
tc =in.next();
System.out.println("Forma de pago: ");
fp=in.next();
if(tc=="G")
{
if(fp=="C")
{
m = mc * DESC_G;
tp = mc - m;
r = "DESCUENTO 15%";
}
else
{
m = mc * REC_G;
tp = mc + m;
r = "RECARGO 10%";
}
}
else
{
if (fp=="C")

23. {
m = mc * DESC_A;
tp = mc - m;
r = "DESCUENTO 20%";
}
else
{
m= mc * REC_A;
tp = mc + m;
r = "RECARGO 5%";
}
}
System.out.println("");
System.out.println(r + ": "+m);
System.out.println("Total a pagar: " + tp);
System.out.println();
}
}

24. 23°
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package problema023;
import java.io.*;
/**
*
* @author ERIKA
*/
public class PROBLEMA023 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException{
float a,b,x;
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.println("a: ");
a=Float.parseFloat(in.readLine());
System.out.println("b: ");
b=Float.parseFloat(in.readLine());
if(a!=0)
{
x=-b/a;
}
else
{
x=0;
}
System.out.println("");
System.out.println("x: " + x);
System.out.println();
}
}

25. 24°
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package problema024;
import java.io.*;
/**
*
* @author ERIKA
*/
public class Problema024 {
/**
* @param args the command line arguments
*/
public static void main(String[] args)throws IOException {
double a,b,c,d,x1,x2;
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.println("a: ");
a=(double) Integer.parseInt(in.readLine());
System.out.println("b: ");
b=(double)Integer.parseInt(in.readLine());
System.out.println("c: ");
c=(double) Integer.parseInt(in.readLine());
d = Math.pow(b,2)-4*c;
if(a!=0 && d>=0)
{
x1 = (-b+Math.pow(d,(1.0/2)))/2*a;
x2 = (-b-Math.pow(d,(1.0/2)))/2*a;
}
else
{
x1 = 0;
x2 = 0;
}
System.out.println("");
System.out.println("x1: " + x1);
System.out.println("x2: " + x2);
System.out.println();
}
}

26. 25°/*
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*/
package problema0025;
import java.io.*;
/**
*
* @author ERIKA
*/
public class Problema0025 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
int h,m,s;
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Hora: ");
h= Integer.parseInt(in.readLine());
System.out.println("Minuto: ");
m=Integer.parseInt(in.readLine());
System.out.println("Segundo: ");
s= Integer.parseInt(in.readLine());
s+=1;
if (s==60)
{
s=0;
m+=1;
if(m==60)
{
m=0;
h+=1;
if(h==24)
{
h=0;
}
}
}
System.out.println("");
System.out.println("Hora: " + h);
System.out.println("Minuto: " + m);
System.out.println("Segundo: " + s);
System.out.println();
}
}