//求两个数的平均数，平方根，平方packageshixun;importjava.util.Scanner;publicclassShixun1{publicstaticvoidmain(String[]args){Scannersc=newScanner(System.in);doublea=sc.nextDouble();doubleb=sc.nextDouble();doublec=(a+b)/2;doubled1=Math.sqrt(a);doubled2=Math.sqrt(b);doublec0=a*a;System.out.println(c+"\t"+d1+"\t"+d2+"\t"+c0);}}packageshixun;//输出a,b及其ASCIIpublicclassShixun2{publicstaticvoidmain(String[]args){charx1='a';intx2=97;inty2=x1+1;chary1=(char)y2;System.out.println(x1+"\t"+x2+"\t"+y1+"\t"+y2);}}//判断三个数的最大数packageshixun;importjava.util.Scanner;publicclassShixun3{publicstaticvoidmain(String[]args){Scannersc=newScanner(System.in);inta=sc.nextInt();intb=sc.nextInt();intc=sc.nextInt();intmax=a;if(a>b)if(a>c)max=a;elsemax=c;elseif(b>c)max=b;elsemax=c;System.out.print(max);}}packageshixun;//显示200以内能被5或6整除，但不能被两者同时整除的数publicclassShixun4{publicstaticvoidmain(String[]args){intk=0;for(inti=1;i<200;i++)if(((i%5==0)&&(i%6!=0))||((i%5!=0)&&(i%6==0))){System.out.print(i+"\t");k++;if(k%5==0)System.out.println();}}}packageshixun;//1！到10！publicclassShixun5{publicstaticvoidmain(String[]args){inti=1,j=1,sum=0;do{j=j*i;sum=sum+j;i++;}while(i<=10);System.out.println(sum);}}//编程实现简易计算器，根据+-*/运算符，对两数执行相应的运算packageshixun;importjava.util.Scanner;publicclassShixun6{publicstaticvoidmain(String[]args){Scannerinput=newScanner(System.in);System.out.print("请输入第一个操作数：");doublenum1=input.nextInt();System.out.print("请输入第二个操作数：");doublenum2=input.nextInt();System.out.print("运算符：");StringfuHao=input.next();charc=fuHao.charAt(0);doublenum3=0;switch(c){case'+':num3=num1+num2;break;case'-':num3=num1-num2;break;case'*':num3=num1*num2;break;case'/':num3=num1/num2;break;default:System.out.println("输入符号错误");}System.out.println(num1+fuHao+num2+"="+num3);}}//判断21世纪闰年的个数packageshixun;publicclassShixun7{publicstaticvoidmain(String[]args){intk=0;for(inti=2000;i<=2100;i++)if(i%400==0||i%4==0&&i%100!=0){System.ou