java第六次作业
1.使用for循环计算1-100的和,除了以3结尾的那些数
package apex; import java.util.Scanner; public class apex { 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.使用二重循环输出以下图形
*
***
*****
*******
*****
****
***
**
*
package apex; import java.util.Scanner; public class apex { public static void main(String[] args) { // TODO Auto-generated method stub for (int i = 1; i <= 4; i++) { for (int j = 1; j <= 7 - i; j++) { System.out.print(" "); } for (int k = 1; k <= 2 * i - 1; k++) { System.out.print("*"); } System.out.println(); } System.out.println(" "); for (int a = 1; a <= 5; a++) { for (int b = 1; b <= 6 - a; b++) { System.out.print("*"); } System.out.println(" "); } } }
3.循环输入学生姓名,直到输入‘Q’程序结束。
package apex; import java.util.Scanner; public class apex { public static void main(String[] args) { // TODO Auto-generated method stub Scanner input=new Scanner(System.in); String name=input.next(); do { name=input.next(); } while (!name.equals("q")); System.out.println("结束"); } }
4.输入5个学生成绩,求和,当输入不合法的时候,提示输入错误重新输入。
package apex; import java.util.Scanner; public class apex { public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); int sum = 0; for (int i = 0; i <= 5; i++) { System.out.println("输入学生成绩"); int a = input.nextInt(); if (a < 0 || a > 100) { System.out.println("输入不合法\n请重新输入"); } else { sum += a; } } System.out.println(sum); } }
5.计算 1+1/(1+2) + 1/(1+2+3) +1/(1+2+3+4)+…………+1/(1+2+....+10)
package apex; import java.util.Scanner; public class apex { public static void main(String[] args) { // TODO Auto-generated method stub double sum=0; double x=0; for(int y=1;y<=10;y++){ sum+=y; x=1/sum+x; } System.out.println(x); } }
作业
1.产生一个1-99的随机数,猜数字,若大了就提示“大了点”,若小了就提示“小了点”直到猜对为止。
(判断猜的次数,如果1-3次,提示太棒了 如果5-8次 一般般 如果8次以上 太笨了)
package apex; import java.util.Scanner; public class apex { 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("有一个0到99之间的整数,猜猜是多少?"); int x = 0; do { int y = input.nextInt(); if (y < number) { System.out.println("小了点!"); x++; } else if (y> number) { System.out.println("大了点!"); x++; } else { System.out.println("猜对啦!"); x++; break; } } while (true); System.out.println("这个数字是" + number); System.out.println("您猜的次数是" + x); if (x >= 1 && x <= 3) { System.out.println("太棒了!"); } else if (x >= 5 && x <= 8) { System.out.println("一般般!"); } else { System.out.println("太笨了!"); } } }
2.输入一个数,判断是不是质数(只能被1和自身整除的数)
package apex; import java.util.Scanner; public class apex { public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); System.out.println("输入一个数"); int sum = input.nextInt(); boolean isPrime = true; if (sum == 1) { isPrime = false; } for (int i = 2; i <= sum - 1; i++) { if (sum % i == 0) { isPrime = false; break; } } if (isPrime) { System.out.println(sum + "是质数"); } else { System.out.println(sum + "不是质数"); } } }
3.求裴波纳契数列的第20项是什么。(裴波纳契数列,1,1,2,3,5,8,13,21······)
package apex; public class apex { public static void main(String[] args) { // TODO Auto-generated method stub int a = 1; int b = 1; int sum = 0; for (int i = 0; i < 18; i++) { sum = a + b; a = b; b = sum; } System.out.println("裴波那契数列的第20项是\n" + b); } }