package ysl; public class test6 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int sum=0; for(int i=1;i<=100;i++){ int j=i%10; if(j!=3){ sum=sum+i; } }System.out.println("和为"+sum); } }
2.使用二重循环输出以下图形
*
***
*****
*******
*****
****
***
**
*
(1)
package ysl; public class test6 { /** * @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(); } } }
(2)
package ysl; public class test6 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub for(int i=1;i<=5;i++){ for(int j=6-i;j>0;j--){ 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 ysl; import java.util.Scanner; public class test66 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input=new Scanner(System.in); System.out.println("输入学生姓名"); String name=input.next(); while(true){ if(name.equals("Q")){ System.out.println("程序结束"); break; }else{ name=input.next(); } } } }
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 ysl; import java.util.Scanner; public class test66 { /** * @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. 计算 1+1/1+2+1/1+2+3+1/1+2+3+4+…………+1/1+2+....+10
package ysl; public class test6 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub double sum = 0; double sum1 = 0; for (int i = 1; i <= 10; i++) { sum += i; sum1 = 1 / sum + sum1; } System.out.println(sum1); } }
6.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 ysl; import java.util.Random; import java.util.Scanner; public class test { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); System.out.println("猜数"); int num = input.nextInt(); Random r = new Random(); int x = r.nextInt(100); int ci =0; while (num != x) { if (num > x) { System.out.println("大一点"); } else if (num < x) { System.out.println("小一点"); } num = input.nextInt(); ci++; } if(num==x){ } if(ci<=3){ System.out.println("太棒了"); }else if(ci>=4&&ci<=8){ System.out.println("一般般"); }else{ System.out.println("太笨了"); } System.out.println("正确答案是"+x); System.out.println("猜的次数为"+ci); } }
7.输入一个数,判断是不是质数(只能被1和自身整除的数是质数)
package ysl; import java.util.Scanner; public class test66 { /** * @param args */ 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 num = input.nextInt(); boolean isPrime = true; if (num == 1) { isPrime = false; } for (int i = 2; i <= num - 1; i++) { if (num % i == 0) { isPrime = false; break; } } if (isPrime) { System.out.println(num + "是质数"); } else { System.out.println(num + "不是质数"); } } }
8.求裴波那契数列的第20项是什么。裴波那契数列,1,1,2,3,5,8,13,21……
package ysl; public class test6 { /** * @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=1;i<=18;i++){ c=a+b; a=b; b=c; } System.out.println("第20项是"+c); } }