Java第六次作业

1.

package mld;

public class Ma {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int sum = 0;
        for (int i = 1; i <= 100; i++) {
            if (i % 10 != 3)
                sum += i;
        }
        System.out.println(sum);
    }

}

 

 

2.

package mld;

public class Ma {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        for (int i = 1; i <= 4; i++) {
            for (int j = 1; j <= 4 - i; j++) {
                System.out.print(" ");
            }
            for (int k = 1; k <= 2 * i - 1; k++) {
                System.out.print("*");
            }
            System.out.println();
        }
        System.out.println();
        System.out.println();
        System.out.println();
        System.out.println();
        for (int i = 1; i <= 5; i++) {
             for (int j = 1; j <= 6 - i; j++) {
                  System.out.print("*");
        }
        System.out.println();
    }

        
  }
}

 

 

3.

package mld;

import java.util.Scanner;

public class Ma {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入学生的姓名");
        String name = input.next();
        while (name != "Q") {
            name = input.next();
            if (name.equals("Q"))
                break;
        }
        System.out.println("程序结束");
    }

}

 

 

4.

import java.util.Scanner;

public class Ma {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入学生成绩");
        int sum = 0;
        for (int i = 1; i <= 5; i++) {
            int grade = input.nextInt();
            while (grade < 0 || grade > 100) {
                System.out.println("输入的成绩无效，重新输入");
                grade = input.nextInt();
                break;
            }
            sum += grade;
        }
        System.out.println(sum);
    }

}

 

 

5.

package mld;


public class Ma {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        double sum = 0;
        double j = 0;
        for (int i = 1; i <= 10; i++) {
            sum += i;
            j = 1 / sum + j;
        }
        System.out.println(j);
    }

}

 

 

6.

package mld;

import java.util.Random;
import java.util.Scanner;


public class Ma {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        int number = (int) (Math.random() * 100);
        System.out.println("我这里有一个0到99之间的整数，你猜是多少？");
        int a = 0;
        do {
            int b = input.nextInt();
            if (b < number) {
                System.out.println("小了点!");
                a++;
            } else if (b > number) {
                System.out.println("大了点！");
                a++;
            } else {
                System.out.println("猜对啦!");
                a++;
                break;
            }
        } while (true);
        System.out.println("这个数字是" + number);
        System.out.println("您猜的次数是" + a);
        if (a >= 1 && a <= 3) {
            System.out.println("太棒了!");
        } else if (a >= 5 && a <= 8) {
            System.out.println("一般般!");
        } else {
            System.out.println("太笨了!");
        }
}
}

 

 

7.

package mld;

import java.util.Random;
import java.util.Scanner;


public class Ma {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("请输入大于1的数");
        int a = input.nextInt();
        boolean shizhishu = true;
        for (int i = 2; i < a - 1; i++) {
            if (a % i == 0) {
                shizhishu = false;
                break;
            }
        }
        if (shizhishu) {
            System.out.println("是质数");
        } else {
            System.out.println("不是质数");
        }
    }

}

 

 

 

8.

package mld;

public class Ma1 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int a = 1;
        int b = 1;
        int c = 0;
        for (int i = 2; i < 20; i++) {
            c = a + b;
            a = b;
            b = c;
        }
        System.out.println("第20项" + c);
    }

}