第六周作业
1.使用for循环计算1-100的和,除了以3结尾的那些数
package com.wyn; public class HomeWork { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int sum=0; for (int i = 1; i < 101; i++) { if(i == 3 || i%10 == 3){ continue; } sum = sum + i; } System.out.println(sum); } }
2.使用二重循环输出以下图形
*
***
*****
*******
*****
****
***
**
*
package com.wyn; public class HomeWork2 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub for (int i = 1; i < 5; i++) { for (int j = 1; j < 5-i; j++) { System.out.print(" "); } for (int j = 0; j < i+i-1; j++) { System.out.print("*"); } System.out.println(); } } } package com.wyn; public class HomeWork3 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub for (int i = 6; i > 1; i--) { for (int j = 1; j < i; 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 com.wyn; import java.util.Scanner; public class HomeWork4 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner s = new Scanner(System.in); while(true){ System.out.println("输入姓名"); String name = s.next(); if(name.equals("Q")){ break; } } } }
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 com.wyn; import java.util.Scanner; public class HomeWork5 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner s = new Scanner(System.in); int sum=0; int i=0; while(true){ System.out.println("输入成绩"); int cj = s.nextInt(); if(cj>100 || cj<0){ System.out.println("重新输入"); continue; }else{ sum= sum+cj; i++; } if(i==5){ System.out.println(sum); break; } } } }
5.计算 1+1/(1+2) + 1/(1+2+3) +1/(1+2+3+4)+…………+1/(1+2+....+10)
package com.wyn; public class HomeWork6 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub double sum = 0; double fm = 0; for (int i = 1; i <= 10; i++) { fm=fm+i; sum=sum+1/fm; } System.out.println(sum); } }
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 com.wyn; import java.util.Random; import java.util.Scanner; public class A { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Random r = new Random(); Scanner s = new Scanner(System.in); int b =r.nextInt(99)+1; int i=0; while(true){ int a = s.nextInt(); if(a>b){ System.out.println("da"); i++; } if(a<b){ System.out.println("xiao"); i++; } if(a==b){ System.out.println("dui"); i++; break; } } } }
2.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 homework; import java.util.Scanner; public class HomeWork2 { public static void main(String[] args) { // TODO Auto-generated method stub Scanner s =new Scanner(System.in); int a = s.nextInt(); boolean c= true;; for(int b = 2 ; b<a ; b++) { if(a%b==0) { c = false; break; } } if(c) { System.out.println("shi"); }else { System.out.println("bushi"); } } }
3.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 homework; import java.util.Scanner; public class HomeWork2 { public static void main(String[] args) { // TODO Auto-generated method stub int a = 1, b = 1, i; System.out.println("1"); for (i = 1; i < 20; i++) { int t = a; System.out.println(b); a = b; b += t; } } }