Góc thủ thuật sv | Hướng dẫn lập trình java cơ bản | Chia sẻ code

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Bài 5. Viết chương trình liệt kê tất cả các số nguyên tố nhỏ hơn n cho trước.

3:12 AM |
import java.util.Scanner;
public class Main {

    public static void lietKe(int n){
                        System.out.print(" 2");
                        for(int i=3;i<n;i+=2){
                                    if(cachamchung.checkSNT(i))System.out.print(" "+i);
                        }
            }
    public static int nhap(){
                        Scanner input= new Scanner(System.in);
                        boolean check= false;
                        int n=0;
                        while(!check){
                                    System.out.print(" ");
                                    try{
                                                n= input.nextInt();
                                                check= true;
                                    }catch(Exception e){
                                                System.out.println("Ban phai nhap so! hay nhap lai...");
                                                input.nextLine();
                                    }
                        }
                        return (n);
            }
    public static void main(String[] args) {
                System.out.print("Nhap n");
                        int n= nhap();
                        System.out.println("Cac so nguyen to nho hon "+n+ " ");
                        lietKe(n);
    }


}

Bài 4. Viết chương trình phân tích một số nguyên thành các thừa số nguyên tố Ví dụ: Số 28 được phân tích thành 2 x 2 x 7

11:35 AM |















import java.util.Scanner;
public class Main {

   
    public static void phanTich(int n){
                        int i=2;
                        while(n>1){
                                    if(cachamchung.checkSNT(i)){
                                                if(n%i==0){
                                                            System.out.print(i+".");
                                                            n/=i;
                                                }
                                                else i++;
                                    }
                                    else i++;
                        }
            }
    public static int nhap(){
                        Scanner input= new Scanner(System.in);
                        boolean check= false;
                        int n=0;
                        while(!check){
                                    System.out.print(" ");
                                    try{
                                                n= input.nextInt();
                                                check= true;
                                    }catch(Exception e){
                                                System.out.println("Ban phai nhap so! hay nhap lai...");
                                                input.nextLine();
                                    }
                        }
                        return (n);
            }
    public static void main(String[] args) {
        System.out.print("Nhap n");
                        int n= nhap();
                        System.out.print("n= " );
                        phanTich(n);
    }

}
hoc java co ban, mot so bai tap java co ban, hoc java





Bài 3. Hãy viết chương trình tính tổng các chữ số của một số nguyên bất kỳ. Ví dụ: Số 8545604 có tổng các chữ số là: 8+5+4+5+6+0+4= 32.

11:31 AM |

import java.util.Scanner;

public class Main {

   
    public static int nhap(){
                        Scanner input= new Scanner(System.in);
                        boolean check= false;
                        int n=0;
                        while(!check){
                                    System.out.print(" ");
                                    try{
                                                n= input.nextInt();
                                                check= true;
                                    }catch(Exception e){
                                                System.out.println("Ban phai nhap so! hay nhap lai...");
                                                input.nextLine();
                                    }
                        }
                        return (n);
            }
    public static int tinhTong(long i){
                        int sum=0;
                        long n;
                        while(i!=0){
                                    n= i%10;
                                    sum+= n;
                                    i/=10;
                        }
                        return (sum);
            }
    public static void main(String[] args){
                System.out.print("Nhap n");
                        int n= nhap();
                        System.out.println("Tong cua so "+n+" = " +tinhTong(n));
    }


}


Bài 2. Viết chương trình chuyển đổi một số tự nhiên ở hệ cơ số 10 thành số ở hệ cơ số b bất kì (1< b≤ 36).

11:29 AM |











import java.util.Scanner;
public class Main {

    public static void doiCoSo(int n,int base){
        if(n>=base) doiCoSo(n / base, base);
        if(n % base>9) System.out.printf("%c",n%base+55);
        else
        System.out.print((n % base));
    }
    public static int nhap(){
                        Scanner input= new Scanner(System.in);
                        boolean check= false;
                        int n=0;
                        while(!check){
                                    System.out.print(" ");
                                    try{
                                                n= input.nextInt();
                                                check= true;
                                    }catch(Exception e){
                                                System.out.println("Ban phai nhap so! hay nhap lai...");
                                                input.nextLine();
                                    }
                        }
                        return (n);
            }
    public static void main(String[] args) {
                System.out.println("Nhap n");
                        int n= nhap();
                        System.out.println("Nhap vao co so can chuyen sang b");
                        int b= nhap();
                        System.out.println("So " +n+ " chuyen sang co so " +b+ " thanh: ");
                        doiCoSo(n,b);
    }


}


Bài 1. Viết chương trình tìm ước số chung lớn nhất, bội số chung nhỏ nhất của hai số tự nhiên a và b.

10:13 AM |
import java.util.Scanner;
 public class Main {
     public static int nhap()
    {
        Scanner input = new Scanner(System.in);
        boolean check= false;
                        int n=0;
                        while(!check){
                                    System.out.print(" ");
                                    try{
                                                n= input.nextInt();
                                                check= true;
                                    }catch(Exception e){
                                                System.out.println("Ban phai nhap so! hay nhap lai...");
                                                input.nextLine();
                                    }
                        }
                        return (n);
    }
    public static int UCLN(int a, int b){
                        while(a!= b){
                                    if(a>b) a= a-b;
                                    else b= b-a;
                        }
                        return (a);
            }
    public static void main(String[] args) {
        System.out.println("Nhap a");
                        int a = nhap();
                        System.out.println("Nhap b");
                        int b= nhap();
                        System.out.println("Uoc chung lon nhat cua "+a+" va "+b+" la: "+UCLN(a,b));
                        System.out.println("Boi chung nho nhat cua "+a+" va "+b+" la: "+((a*b)/UCLN(a,b)));
    }
 }