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
public class Test1 { /** * @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=sum+i; } System.out.println(sum); } }
// *
// ***
// *****
//*******
public class Test2 { /** * @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 = j + 1) System.out.print(" "); for (int k=1;k<=2*i-1;k++) System.out.print("*"); System.out.println(); } } }
//
//*****
//****
//***
//**
//*
public class Test3 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub for (int i = 5; i >= 0; 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。
import java.util.Scanner; public class Test4 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); while (true) { Scanner in = new Scanner(System.in); System.out.println("输入学生姓名"); String str = in.next(); if (str.equals("Q")){ System.out.println("输入的名字有效"); 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。
import java.util.Scanner; public class Test5 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); int sum = 0; for (int i = 1; i <= 5; i++) { System.out.println("请输入第" + i + "个学生成绩"); int grade = input.nextInt(); while (grade < 0 || grade > 100) { System.out.println("请重新输入第" + i + "个学生成绩"); grade = input.nextInt(); } sum = sum + grade; } System.out.println("总成绩为" + sum); } }
//5.计算 1+ 1/(1+2)+ 1/(1+2+3)+ 1/(1+2+3+4) +…………+1/(1+2+....+10)
public class Test6 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub double sum = 0; double e = 0; for (int i = 1; i <= 10; i++) { sum = sum + 1 / (e + i); e = e + i; } System.out.println(sum); } }
//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)
import java.util.Random; import java.util.Scanner; public class test7 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Random r = new Random(); int x = 1 + r.nextInt(98); Scanner input = new Scanner(System.in); System.out.println("请输入1~99的随机数"); int s = input.nextInt(); int a = 1; while (a >= 1) { if (s > x) { System.out.println("大了点"); int j = input.nextInt(); s = j; a++; } else if (s < x) { System.out.println("小了点"); int j = input.nextInt(); s = j; a++; } else { a++; if (a <= 3) System.out.println("太棒了"); if (a >= 4 || a <= 8) System.out.println("一般般"); if (a > 8) System.out.println("太笨了"); break; } } } }
//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)
import java.util.Scanner; public class Test8 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); System.out.println("请输入一个数"); int a = input.nextInt(); if (a >= 2) { for (int i = 2; i <= a; i++) { if (a % i == 0 && a != i) System.out.println(a + "不是质数"); else System.out.println(a + "是质数"); break; } } else System.out.println(a + "不是质数"); } }
//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……
public class Test9 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a=1; int b=1; int c=1; for(int i=1;i<19;i++){ c=a+b; a=b; b=c; } System.out.println("第20項為"+c); } }