Exercices du chapitre 1

Solution :

public class Exercice12 {
    public static void main(String[] args) {
        int age = 20;
        double prix = 19.99;
        char initiale = 'A';
        boolean disponible = true;

        System.out.println("age = " + age);
        System.out.println("prix = " + prix);
        System.out.println("initiale = " + initiale);
        System.out.println("disponible = " + disponible);
    }
}

Solution :

public class Exercice13 {
    public static void main(String[] args) {
        int a = 17;
        int b = 5;

        System.out.println("Somme = " + (a + b));
        System.out.println("Différence = " + (a - b));
        System.out.println("Produit = " + (a * b));
        System.out.println("Quotient = " + (a / b));
        System.out.println("Reste = " + (a % b));
    }
}

Solution :

import java.util.Scanner;

public class Exercice14 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez un nombre : ");
        int n = sc.nextInt();

        if (n % 2 == 0) {
            System.out.println(n + " est pair.");
        } else {
            System.out.println(n + " est impair.");
        }
        sc.close();
    }
}

Solution :

public class Exercice15 {
    public static void main(String[] args) {
        int somme = 0;
        for (int i = 1; i <= 100; i++) {
            somme = somme + i;
        }
        System.out.println("Somme = " + somme);
    }
}

Solution :

import java.util.Scanner;

public class Exercice16 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        double[] notes = new double[5];
        double somme = 0;

        for (int i = 0; i < notes.length; i++) {
            System.out.print("Note " + (i + 1) + " : ");
            notes[i] = sc.nextDouble();
            somme = somme + notes[i];
        }

        double moyenne = somme / notes.length;
        System.out.println("Moyenne = " + moyenne);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice17 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez un nombre : ");
        int n = sc.nextInt();

        for (int i = 1; i <= 10; i++) {
            System.out.println(n + " x " + i + " = " + (n * i));
        }
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice18 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez un nombre : ");
        int n = sc.nextInt();

        if (n < 0) {
            System.out.println("Négatif");
        } else {
            if (n == 0) {
                System.out.println("Zéro");
            } else {
                System.out.println("Positif");
            }
        }
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice19 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez un nombre : ");
        int n = sc.nextInt();

        String message = (n > 0) ? "Positif" : (n < 0) ? "Négatif" : "Zéro";
        System.out.println(message);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice110 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez n : ");
        int n = sc.nextInt();

        int somme = 0;
        int i = 1;
        while (i <= n) {
            somme = somme + i;
            i++;
        }

        System.out.println("Somme = " + somme);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice111 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Taille du tableau : ");
        int n = sc.nextInt();
        int[] tab = new int[n];

        for (int i = 0; i < n; i++) {
            System.out.print("Valeur " + (i + 1) + " : ");
            tab[i] = sc.nextInt();
        }

        int max = tab[0];
        int min = tab[0];
        for (int valeur : tab) {
            if (valeur > max) {
                max = valeur;
            }
            if (valeur < min) {
                min = valeur;
            }
        }

        System.out.println("Maximum = " + max);
        System.out.println("Minimum = " + min);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice112 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez une chaîne : ");
        String texte = sc.nextLine().toLowerCase();

        int voyelles = 0;
        int consonnes = 0;

        for (int i = 0; i < texte.length(); i++) {
            char c = texte.charAt(i);
            if (c >= 'a' && c <= 'z') {
                if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u' || c == 'y') {
                    voyelles++;
                } else {
                    consonnes++;
                }
            }
        }

        System.out.println("Voyelles = " + voyelles);
        System.out.println("Consonnes = " + consonnes);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice113 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        double[] notes = new double[10];
        double somme = 0;

        for (int i = 0; i < notes.length; i++) {
            System.out.print("Note " + (i + 1) + " : ");
            notes[i] = sc.nextDouble();
            somme = somme + notes[i];
        }

        double moyenne = somme / notes.length;
        int compteur = 0;
        for (double note : notes) {
            if (note > moyenne) {
                compteur++;
            }
        }

        System.out.println("Moyenne = " + moyenne);
        System.out.println("Notes au-dessus de la moyenne = " + compteur);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice114 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez un entier positif : ");
        int n = sc.nextInt();

        int inverse = 0;
        while (n > 0) {
            inverse = inverse * 10 + (n % 10);
            n = n / 10;
        }

        System.out.println("Nombre inversé = " + inverse);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice115 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez n : ");
        int n = sc.nextInt();

        int a = 0;
        int b = 1;
        while (a <= n) {
            System.out.print(a + " ");
            int suivant = a + b;
            a = b;
            b = suivant;
        }
        System.out.println();
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice116 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Rayon : ");
        double rayon = sc.nextDouble();

        double aire = Math.PI * rayon * rayon;
        System.out.println("Aire = " + aire);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice117 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Température en Celsius : ");
        double celsius = sc.nextDouble();

        double fahrenheit = celsius * 9 / 5 + 32;
        System.out.println("Fahrenheit = " + fahrenheit);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice118 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez une phrase : ");
        String phrase = sc.nextLine().trim();

        int mots = 0;
        if (!phrase.isEmpty()) {
            String[] parties = phrase.split("\\s+");
            mots = parties.length;
        }

        System.out.println("Nombre de mots = " + mots);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice119 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez un entier positif : ");
        int n = sc.nextInt();

        long factoriel = 1;
        for (int i = 1; i <= n; i++) {
            factoriel = factoriel * i;
        }

        System.out.println("Factoriel = " + factoriel);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice120 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez n : ");
        int n = sc.nextInt();

        for (int i = 1; i <= n; i++) {
            if (i % 2 == 0) {
                System.out.print(i + " ");
            }
        }
        System.out.println();
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice121 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez une chaîne : ");
        String texte = sc.nextLine();

        String nettoye = texte.replaceAll("[^a-zA-Z0-9]", "").toLowerCase();
        String inverse = new StringBuilder(nettoye).reverse().toString();

        if (nettoye.equals(inverse)) {
            System.out.println("C'est un palindrome.");
        } else {
            System.out.println("Ce n'est pas un palindrome.");
        }
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice122 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Taille du tableau : ");
        int n = sc.nextInt();
        int[] tab = new int[n];

        long produit = 1;
        for (int i = 0; i < n; i++) {
            System.out.print("Valeur " + (i + 1) + " : ");
            tab[i] = sc.nextInt();
            produit = produit * tab[i];
        }

        System.out.println("Produit = " + produit);
        sc.close();
    }
}

Solution :

import java.util.Arrays;
import java.util.Scanner;

public class Exercice123 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Taille du tableau : ");
        int n = sc.nextInt();
        int[] tab = new int[n];

        for (int i = 0; i < n; i++) {
            System.out.print("Valeur " + (i + 1) + " : ");
            tab[i] = sc.nextInt();
        }

        Arrays.sort(tab);
        System.out.println("Tableau trié : " + Arrays.toString(tab));
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice124 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Premier nombre : ");
        double a = sc.nextDouble();
        System.out.print("Deuxième nombre : ");
        double b = sc.nextDouble();
        System.out.print("Opérateur (+ - * /) : ");
        char op = sc.next().charAt(0);

        switch (op) {
            case '+':
                System.out.println("Résultat = " + (a + b));
                break;
            case '-':
                System.out.println("Résultat = " + (a - b));
                break;
            case '*':
                System.out.println("Résultat = " + (a * b));
                break;
            case '/':
                if (b == 0) {
                    System.out.println("Division par zéro impossible.");
                } else {
                    System.out.println("Résultat = " + (a / b));
                }
                break;
            default:
                System.out.println("Opérateur invalide.");
        }
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice125 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez un entier : ");
        int n = Math.abs(sc.nextInt());

        int somme = 0;
        while (n > 0) {
            somme = somme + (n % 10);
            n = n / 10;
        }

        System.out.println("Somme des chiffres = " + somme);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice126 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Nombre de lignes : ");
        int n = sc.nextInt();

        for (int i = 0; i < n; i++) {
            int valeur = 1;
            for (int j = 0; j <= i; j++) {
                System.out.print(valeur + " ");
                valeur = valeur * (i - j) / (j + 1);
            }
            System.out.println();
        }
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice127 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Taille du tableau : ");
        int n = sc.nextInt();
        int[] tab = new int[n];

        for (int i = 0; i < n; i++) {
            System.out.print("Valeur " + (i + 1) + " : ");
            tab[i] = sc.nextInt();
        }

        int max = Integer.MIN_VALUE;
        int second = Integer.MIN_VALUE;
        for (int valeur : tab) {
            if (valeur > max) {
                second = max;
                max = valeur;
            } else if (valeur > second && valeur < max) {
                second = valeur;
            }
        }

        if (second == Integer.MIN_VALUE) {
            System.out.println("Pas de second maximum distinct.");
        } else {
            System.out.println("Second maximum = " + second);
        }
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice128 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Nombre de lignes : ");
        int lignes = sc.nextInt();
        System.out.print("Nombre de colonnes : ");
        int colonnes = sc.nextInt();

        int[][] matrice = new int[lignes][colonnes];
        for (int i = 0; i < lignes; i++) {
            for (int j = 0; j < colonnes; j++) {
                System.out.print("matrice[" + i + "][" + j + "] = ");
                matrice[i][j] = sc.nextInt();
            }
        }

        int somme = 0;
        for (int[] ligne : matrice) {
            for (int valeur : ligne) {
                somme = somme + valeur;
            }
        }

        System.out.println("Somme = " + somme);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice129 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez un nombre (0-99) : ");
        int n = sc.nextInt();

        String[] unites = {
            "zéro", "un", "deux", "trois", "quatre", "cinq", "six", "sept", "huit", "neuf",
            "dix", "onze", "douze", "treize", "quatorze", "quinze", "seize",
            "dix-sept", "dix-huit", "dix-neuf"
        };
        String[] dizaines = {
            "", "", "vingt", "trente", "quarante", "cinquante",
            "soixante", "soixante", "quatre-vingt", "quatre-vingt"
        };

        String resultat;
        if (n < 0 || n > 99) {
            resultat = "Nombre hors intervalle";
        } else if (n < 20) {
            resultat = unites[n];
        } else {
            int d = n / 10;
            int u = n % 10;
            if (d == 7 || d == 9) {
                resultat = dizaines[d] + "-" + unites[10 + u];
            } else if (u == 0) {
                resultat = dizaines[d] + (d == 8 ? "s" : "");
            } else if (u == 1 && d != 8) {
                resultat = dizaines[d] + "-et-un";
            } else {
                resultat = dizaines[d] + "-" + unites[u];
            }
        }

        System.out.println(resultat);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice130 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Nombre de lignes : ");
        int n = sc.nextInt();

        for (int i = 1; i <= n; i++) {
            for (int e = 1; e <= n - i; e++) {
                System.out.print(" ");
            }
            for (int j = 1; j <= i; j++) {
                System.out.print(j + " ");
            }
            System.out.println();
        }
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice131 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez n : ");
        int n = sc.nextInt();

        int somme = 0;
        for (int i = 1; i <= n; i++) {
            somme = somme + (i * i);
        }

        System.out.println("Somme des carrés = " + somme);
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice132 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez un entier positif : ");
        int n = sc.nextInt();

        int somme = 0;
        for (int i = 1; i < n; i++) {
            if (n % i == 0) {
                somme = somme + i;
            }
        }

        if (somme == n && n > 0) {
            System.out.println(n + " est un nombre parfait.");
        } else {
            System.out.println(n + " n'est pas un nombre parfait.");
        }
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice133 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Premier terme : ");
        int a = sc.nextInt();
        System.out.print("Différence : ");
        int d = sc.nextInt();
        System.out.print("Nombre de termes : ");
        int n = sc.nextInt();

        for (int i = 0; i < n; i++) {
            System.out.print((a + i * d) + " ");
        }
        System.out.println();
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice134 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez un entier : ");
        int n = sc.nextInt();

        System.out.print("Facteurs : ");
        for (int i = 1; i <= Math.abs(n); i++) {
            if (n % i == 0) {
                System.out.print(i + " ");
            }
        }
        System.out.println();
        sc.close();
    }
}

Solution :

import java.util.Random;

public class Exercice135 {
    public static void main(String[] args) {
        String caracteres =
            "ABCDEFGHIJKLMNOPQRSTUVWXYZ" +
            "abcdefghijklmnopqrstuvwxyz" +
            "0123456789" +
            "!@#$%&*?";

        Random alea = new Random();
        StringBuilder motDePasse = new StringBuilder();

        for (int i = 0; i < 8; i++) {
            int index = alea.nextInt(caracteres.length());
            motDePasse.append(caracteres.charAt(index));
        }

        System.out.println("Mot de passe : " + motDePasse);
    }
}

Solution :

import java.util.Scanner;

public class Exercice136 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Taille du tableau : ");
        int n = sc.nextInt();
        int[] tab = new int[n];

        for (int i = 0; i < n; i++) {
            System.out.print("Valeur " + (i + 1) + " : ");
            tab[i] = sc.nextInt();
        }

        for (int i = 0; i < n / 2; i++) {
            int tmp = tab[i];
            tab[i] = tab[n - 1 - i];
            tab[n - 1 - i] = tmp;
        }

        System.out.print("Tableau inversé : ");
        for (int valeur : tab) {
            System.out.print(valeur + " ");
        }
        System.out.println();
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice137 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Entrez un entier : ");
        int n = sc.nextInt();

        boolean premier = n > 1;
        for (int i = 2; i * i <= n; i++) {
            if (n % i == 0) {
                premier = false;
                break;
            }
        }

        if (premier) {
            System.out.println(n + " est premier.");
        } else {
            System.out.println(n + " n'est pas premier.");
        }
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice138 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Nombre de secondes : ");
        int total = sc.nextInt();

        int heures = total / 3600;
        int minutes = (total % 3600) / 60;
        int secondes = total % 60;

        System.out.println(heures + " h " + minutes + " min " + secondes + " s");
        sc.close();
    }
}

Solution :

import java.util.Scanner;

public class Exercice139 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("x1 : ");
        double x1 = sc.nextDouble();
        System.out.print("y1 : ");
        double y1 = sc.nextDouble();
        System.out.print("x2 : ");
        double x2 = sc.nextDouble();
        System.out.print("y2 : ");
        double y2 = sc.nextDouble();

        double distance = Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2));
        System.out.println("Distance = " + distance);
        sc.close();
    }
}

Solution :

public class Exercice140 {
    public static void main(String[] args) {
        boolean[] valeurs = {false, true};

        System.out.println("a\tb\ta && b\ta || b");
        for (boolean a : valeurs) {
            for (boolean b : valeurs) {
                System.out.println(a + "\t" + b + "\t" + (a && b) + "\t" + (a || b));
            }
        }

        System.out.println();
        System.out.println("a\t!a");
        for (boolean a : valeurs) {
            System.out.println(a + "\t" + (!a));
        }
    }
}