#include <iostream>
#include <string>
using namespace std;
 
int main ()
{
    string str("one three two four");
    string str2("three");
    str.replace(str.find(str2),str2.length(),"five");
    cout << str << endl;
    return 0;
}

#include <iostream>
#include <stdlib.h>
#include <string>
#include <fstream>
using namespace std;
 
int main() {
  ifstream in("archivo.txt"); // Open for reading
  ofstream out("j.txt"); // Open for writing
  string s;
  string re("   ");
  while(getline(in, s)) // Discards newline char
 
    s.replace(s.find(re),re.length(),"");
    out << s << "\n"; // ... must add it back
 
  system("pause>nul");
}
 
 

#include <stdio.h>
 
void main(){
        char temp[10];
        int a = 5;
 
        while(a == a){
            printf(">>> ");
            scanf("%s", &temp);
 
        }        
    }
 

>>>

>>> palabra1

>>>

>>> palabra1 palabra2 palabra3 palabra4

>>> >>> >>> >>>

public static void stop_it(){
		if (max_altura == 504){
			timer.cancel();
	        timer.purge();
		}

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Timer;
import java.util.TimerTask;
 
 
public class MyClass {
 
	static Timer timer = new Timer();
 
	static short max_altura = 6;
	static short max_ancho = 386;
 
	static short min_altura = 504;
	static short min_ancho = 386;
 
	static float vi_val = 0f;
	static float con_accel = 9.8f;
	static float up = 500f;
	static float cielito = 500f;
 
	static JLabel uper = new JLabel("500.0 m");
	static JLabel mid = new JLabel("250.0 m");
	static JTextField altura = new JTextField("500");
	static JTextField accel = new JTextField("9.8");
	static JTextField vi = new JTextField("0");
	static JLabel ball = new JLabel();
	static JFrame frame = new JFrame("KuroNeko Fall Simulator 1.0");
	static JLabel scale = new JLabel();
	static JComboBox dir = new JComboBox();
 
 
 
 
	static boolean pause_val = false;
 
 
 
	public static void main(String args[]){
 
		frame.setLayout(null);
		frame.setSize(800, 565);
		frame.setResizable(false);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
		JLabel label1 = new JLabel("Altura maxima (m)");
		label1.setBounds(10, 20, 110, 20);
		//altura
		altura.setBounds(140, 20, 200, 20);
 
 
 
		JLabel label3 = new JLabel("Aceleracion (m/s²)");
		label3.setBounds(10, 50, 110, 20);
		//accel
		accel.setBounds(140, 50, 200, 20);
 
		JLabel label4 = new JLabel("Velocidad inicial (m/s)");
		label4.setBounds(10, 80, 140, 20);
		//vi
		vi.setBounds(140, 80, 200, 20);
 
		//scale
		scale.setBounds(400, 20, 50, 500);
		scale.setIcon(new ImageIcon("img/scale.png"));
 
		//ball
		ball.setBounds(max_ancho, max_altura, 30, 30);
		ball.setIcon(new ImageIcon("img/ball.png"));
 
		JButton start = new JButton("Iniciar");
		start.setBounds(10, 230, 330, 20);
		start.addActionListener(new ActionListener() {
 
			@Override
			public void actionPerformed(ActionEvent arg0) {
 
 
				TimerTask task = new TimerTask(){
					public void run(){
 
						stop_it();
						Math.pow(1, 2);
						Math.sqrt(100);
						max_altura += 1;
						ball.setBounds(max_ancho, max_altura, 30, 30);
						frame.revalidate();
						frame.repaint();
						System.out.println("hoiwi :3");
 
 
 
 
					}
 
				};
 
				timer.schedule(task, 0, 20);
 
			}
		});
 
		JButton set_val = new JButton("Establecer estos valores");
		set_val.setBounds(10, 200, 330, 20);
		set_val.addActionListener(new ActionListener() {
 
			@Override
			public void actionPerformed(ActionEvent arg0) {
 
				up = Float.valueOf(altura.getText());
				con_accel = Float.valueOf(accel.getText());
				vi_val = Float.valueOf(vi.getText());
 
 
 
				uper.setText(String.valueOf(up) + " m");
				mid.setText(String.valueOf(up / 2) + " m");
 
				max_altura = 6;
				ball.setBounds(max_ancho, max_altura, 30, 30);
				frame.revalidate();
				frame.repaint();
 
 
			}
		});
 
		JButton pause = new JButton("Pausar");
		pause.setBounds(10, 260, 330, 20);
		pause.addActionListener(new ActionListener() {
 
			@Override
			public void actionPerformed(ActionEvent arg0) {
 
 
			}
		});
 
 
		//uper
		uper.setBounds(max_ancho+50, max_altura-10, 200, 50);
		//mid
		mid.setBounds(max_ancho+50, 245, 200, 50);
		JLabel down = new JLabel(String.valueOf(0) + " m");
		down.setBounds(min_ancho+50, min_altura-10, 200, 50);
 
		//dir
		JLabel label5 = new JLabel("Direccion de la pelota");
		label5.setBounds(10, 110, 150, 20);
		dir.setBounds(140, 110, 200, 20);
		dir.addItem("Hacia abajo");
		dir.addItem("Hacia arriba");
		dir.addActionListener(new ActionListener() {
 
			@Override
			public void actionPerformed(ActionEvent e) {
 
 
			}
		});
 
 
		frame.add(label5);
		frame.add(dir);
		frame.add(uper);
		frame.add(mid);
		frame.add(down);
		frame.add(altura);
		frame.add(accel);
		frame.add(start);
		frame.add(set_val);
		frame.add(scale);
		frame.add(ball);
		frame.add(pause);
		frame.add(label4);
		frame.add(vi);		
		frame.add(label1);
		frame.add(label3);
		frame.setVisible(true);
	}
 
	public static void stop_it(){
		if (max_altura == 504){
			timer.cancel();
	        timer.purge();
		}
	}
 
 
 
}