Doubt with exercises with Java maps

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Doubt with exercises with Java maps

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Suppose there is a trend dictionary with a string representing a date (mm-dd-yyyy) as a key and as a value a set of tags (hashtags) that were trends on Twitter for that date. For example:

trends = {'08 -22-2016 ': {' # Rio2016 ',' #BSC ',' #ECU '}, '08 -25-2016 ': {' # GYE ',' #BRA '}, ..., '08 -27- 2016': {'# YoSoyEspol', '#GYE', '#BSC'}}

Implement:

a) report Trends (trends, date list) that the trend dictionary receives and a list with strings that represent dates (mm-dd-yyyy). The function should show on screen:

1) The labels that were trending all dates in the Date list
2) The labels that were trending at least on one of the dates in the Date list

 public static void reportaTendencias(HashMap<String, LinkedList<String>> 
     m, LinkedList<String> l) {
            for (String clave : m.keySet()) {
                for (String valor : m.get(clave)) {
                System.out.println("fecha: " + clave + "," + "etiquetas: " + valor);
            }
        }
    }

I did this for literal 1 and it works but I do not know if it's efficient and 2 I'm not sure how to do it.

b) Excluding trends (trends, date1, date2) that the trend dictionary receives and two strings that represent dates (mm-dd-yyyy). The function should show the labels on the screen which were trends or on date1 or date2, but not both. Note: suppose that date1 and date2 exist in the dictionary as keys.

  public static void tendenciasExcluyentes(HashMap<String, 
 LinkedList<String>> m, String fecha1, String fecha2) {
       LinkedList<String> lista = new LinkedList();
        if (m.containsKey(fecha1)) {
             System.out.println(m.get(fecha1));
       }
   }
 }

And for this I'm not sure how to continue

java

asked by Michelle 17.02.2018 в 01:33

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1 answer

Is it normal for the combobox to appear that way? c # LocationListener destroy

score 0 · Accepted Answer

I think you were raising the problem wrong. On the one hand, you have to use the list of dates that pass you by parameter.

As I imagine it is part of the structure test exercise, here I give you a solution using the same structure for auxiliary purposes.

/ * a) report Trends (trends, date list) that the trend dictionary receives and a list with strings that represent dates (mm-dd-yyyy). The function should show on screen:

1) Las etiquetas que fueron tendencia todas las fechas en listaFechas
2) Las etiquetas que fueron tendencia al menos en una de las fechas en listaFechas

 */
public static void reportaTendencias(Map<String, LinkedList<String>> m, LinkedList<String> l) {
    System.out.println("Ejercicio A, apartado 1");
    // Recorrermos las fechas que nos pasan por parametro
    Map<String, Integer> coincidencias = new HashMap<>(); //Recuerda que en Maps la Key no puede repetirse
    for (String clave : l) {
        //Obtenemos el valor asociado a la clave de la fecha
        for (String valor : m.get(clave)) {
            // Si el valor ya existe en nuestro mapeo coincidencias, simplemente aumentamos el numero de veces encontrado
            if (coincidencias.containsKey(valor)) {
                coincidencias.put(valor, coincidencias.get(valor) + 1);
            } else {
                // En caso contrario debemos meter el valor nuevo
                coincidencias.put(valor, 1);
            }
        }
    }
    // Imprimimos solo aquellos valores que hayan aparecido en TODAS las fechas
    for (String valor : coincidencias.keySet()) {
        if (coincidencias.get(valor) == l.size()) {
            System.out.print(valor + " ");
        }
    }
    System.out.println("");
    //Recorremos la lista de fechas y guardamos el valor
    System.out.println("Ejercicio A, apartado 2");
    coincidencias.clear();
    for (String clave : l) {
        for (String valor : m.get(clave)) {
            coincidencias.put(valor, 1);
        }
    }

    // Imprimimos los valores una unica vez
    for (String valor : coincidencias.keySet()) {
        System.out.print(valor + " ");
    }
    System.out.println("");
}

public static void tendenciasExcluyentes(Map<String, LinkedList<String>> m, String fecha1, String fecha2) {
    System.out.println("Ejercicio B");
    Map<String, Integer> coincidencias = new HashMap<>(); //Recuerda que en Maps la Key no puede repetirse
    for (String clave : m.keySet()) {
        //Solo comprobaremos aquellos que coincidan con las fechas pasadas por parametro
        if (clave.equals(fecha1) || clave.equals(fecha2)) {
            for (String valor : m.get(clave)) {
                // Si el valor ya existe en nuestro mapeo coincidencias, simplemente aumentamos el numero de veces encontrado
                if (coincidencias.containsKey(valor)) {
                    coincidencias.put(valor, coincidencias.get(valor) + 1);
                } else {
                    // En caso contrario debemos meter el valor nuevo
                    coincidencias.put(valor, 1);
                }
            }
        }
    }
    // NOTA: Ponemos 1 porque solo permitimos que apareza una vez
    for (String valor : coincidencias.keySet()) {
        if (coincidencias.get(valor) == 1) {
            System.out.print(valor + " ");
        }
    }

}