cours-info/utils/Utils.java

package utils;

import java.util.Arrays;
import java.util.stream.Collectors;
import java.util.Scanner;
import java.util.function.BiFunction;

public class Utils {

  public static final char[] ALPHABET = new char[] {
    'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
    'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'
  };

  public static String[] CESAR_DATA_CLEAR = new String[] {
    "quitte moi quittons nous juste un peu trop longtemps",
    "pour que nous ressentions le bonheur d etre triste"
  };

  public static int[] CESAR_DATA_KEYS = new int[] {
    7, 9
  };

  public static String[] CESAR_DATA_CRYPT = new String[] {
    "xbpaal tvp xbpaavuz uvbz qbzal bu wlb ayvw svunaltwz",
    "yxda zdn wxdb anbbnwcrxwb un kxwqnda m ncan carbcn"
  };

  public static int[] TEST_SOMME2 = new int[] {
    0, 3, 6,
    3, 7, 25,
    7, 3, 25,
  };

  public static void testSomme2(BiFunction<Integer, Integer, Integer> func) {
    for (int i=0; i<TEST_SOMME2.length; i+=3) {
      int n=TEST_SOMME2[i];
      int p=TEST_SOMME2[i+1];
      int s=TEST_SOMME2[i+2];

      afficher("n = ", n, "p = ", p);
      afficher("*** SOMME:   ", func.apply(n, p));
      afficher("    Attendu: ", s);
    }
  }

  public static final void afficher(Object... args) {
    if (args == null) {
      System.out.println("null");
    } else {
      String str = Arrays.stream(args)
        .map(String::valueOf)
        .collect(Collectors.joining(" "));
      System.out.println(str);
    }
    System.out.print(' ');
  }
  public static final void afficherTabInt(int... args) {
    if (args == null) {
      System.out.println("null");
    } else {
      String str = Arrays.stream(args)
        .boxed()
        .map(i -> i+"")
        .collect(Collectors.joining(" "));
      System.out.println(str);
    }
    System.out.print(' ');
  }

  public static int lireEntier() {
    try (Scanner reader = new Scanner(System.in)) {
      System.out.println("Saisir un entier: ");
      return reader.nextInt();
    }
  }

  public static String lireChaine() {
    try (Scanner reader = new Scanner(System.in)) {
      System.out.println("Saisir une valeur et valider: ");
      return reader.nextLine();
    }
  }

  public static int position(char c) {
    for (int i = 0; i<ALPHABET.length; i++) {
      if (ALPHABET[i] == c) {
        return i;
      }
    }
    afficher("erreur", c);
    return -1;
  }

  public static void testCesar(BiFunction<char[], Integer, char[]> func,
    boolean chiffre) {
    for (int i = 0; i<CESAR_DATA_KEYS.length; i++) {
      int cle = CESAR_DATA_KEYS[i];
      if (chiffre) {
        String result = String.valueOf(func.apply(CESAR_DATA_CLEAR[i]
          .toCharArray(), cle));
        afficher("Clair:   " + CESAR_DATA_CLEAR[i]);
        afficher("Chiffré: " + result);
        afficher("Succès: " + String.valueOf(CESAR_DATA_CRYPT[i]).equals(result));
      } else {
        String result = String.valueOf(func.apply(CESAR_DATA_CRYPT[i]
          .toCharArray(), cle));
        afficher("Chiffré: " + CESAR_DATA_CRYPT[i]);
        afficher("Clair:   " + result);
        afficher("Succès: " + String.valueOf(CESAR_DATA_CLEAR[i]).equals(result));
      }
      afficher();
    }
  }

}