money=money+money*rate/1200;
System.out.println(i+"\t\t"+money);
}
}
}
5.34剪刀石头布
publicclassGame{
privatestaticinti=0;
privatestaticintj=0;
publicstaticvoidmain(String[]args){
for(intn=1;n<100;n++){
System.out.println("输入一个数:
0是剪刀,1是石头,2是布");Scannerin=newScanner(System.in);
System.out.print("请输入你的选择:
");
intchoose=in.nextInt();
intcomputer=(int)(Math.random()*3+0);
System.out.println("电脑的选择:
"+computer);
game(choose,computer);
if(i==2||j==2){System.out.print("游戏结束");break;}System.out.println();
}
}
publicstaticvoidgame(intn1,intn2){
if(n1==n2){
System.out.println("平局");
}elseif(n1==0){
if(n2==1){j++;System.out.println("你输了!
");
}else{i++;System.out.println("你赢了!
");}
}elseif(n1==1){
if(n2==0){i++;System.out.println("你赢了!
");
}else{j++;System.out.println("你输了!
");}
}else{
if(n2==0){j++;System.out.println("你输了!
");
}else{i++;System.out.println("你赢了!
");}
}
}
}
5.45计算平均值和标准方差
publicclassTongJi{
publicstaticvoidmain(String[]args){
inti=10;
doublesum=0;
doublemean;
doublenum=0;
doublestandard;
doublelist[]=newdouble[i];
System.out.print("请输入10个数:
");
Scannerin=newScanner(System.in);
for(i=0;i<10;i++){
list[i]=in.nextDouble();
sum+=list[i];
num+=Math.pow(list[i],2);
}
mean=sum/10;
doublea=num-Math.pow(sum,2)/i;
standard=Math.pow(a/(i-1),0.5);
System.out.println("平均值是:
"+mean);
System.out.print("方差是:
"+standard);
}
}
5.47商业:
检测ISBN-13
publicclassText{
publicstaticvoidmain(String[]args){
Scannerin=newScanner(System.in);
System.out.print("请输入ISBN-13:
");
Stringstr=in.next();
intlength=str.length();
if(length!
=12){System.out.println("请输入正确的ISBN-13码");}
chard1=str.charAt(0);chard2=str.charAt
(1);chard3=str.charAt
(2);
chard4=str.charAt(3);chard5=str.charAt(4);chard6=str.charAt(5);
chard7=str.charAt(6);chard8=str.charAt(7);chard9=str.charAt(8);
chard10=str.charAt(9);chard11=str.charAt(10);chard12=str.charAt(11);
intd=10-(d1-48+(d2-48)*3+d3+(d4-48)*3+d5+(d6-48)*3
+d7+(d8-48)*3+d9+(d10-48)*3+d11+(d12-48)*3)%10;if(d==10){
intd13=0;
System.out.print
("ISBN-13是:
"+d1+d2+d3+d4+d5+d6+d7+d8+d9+d10+d11+d12+d13);
}else{System.out.print
("ISBN-13是:
"+d1+d2+d3+d4+d5+d6+d7+d8+d9+d10+d11+d12+d);
}
}
}
6.7计算未来投资回报值
publicclassMoney{
publicstaticvoidmain(String[]args){
Scannerin=newScanner(System.in);
System.out.print("请输入本金:
");
doubleinvestmentAmount=in.nextDouble();
System.out.print("请输入利率:
");
doublemonthlyInterestRate=in.nextDouble();
System.out.print("请输入年份:
");
intyears=in.nextInt();
futureInvestementValue(investmentAmount,monthlyInterestRate,years);
}
publicstaticdoublefutureInvestementValue(doubleinvestmentAmount,doublemonthlyInterestRate,intyears){
System.out.println("Years\t\tFutureValue");
for(inti=1;idouble
value=investmentAmount*Math.pow(1+monthlyInterestRate/1200,12);
investmentAmount=value;
System.out.println(i+"\t\t"+value);
}
return0;
}
}
6.9英尺和米之间的转换
publicclassMeters{
publicstaticvoidmain(String[]args){System.out.println("英尺\t\t米\t\t\t\t米\t\t英尺");for(inti=1,j=20;i<11;i++,j+=5){
System.out.println(i+"\t\t"+footToMeters(i)+"\t\t\t"+j+"\t\t"+meterToFoot(j));
}
}
publicstaticdoublefootToMeters(doublefoot){
doublemeter=0.305*foot;
returnmeter;
}
publicstaticdoublemeterToFoot(doublemeter){
doublefoot=3.279*meter;
returnfoot;
}
}
6.14估算π
publicclassPi{
publicstaticvoidmain(String[]args){
mathToPi
(1);
}
publicstaticvoidmathToPi(intj){
System.out.println("i\t\tm(i)");
for(;j<1000;j+=100){
doublesum=0;
doublem;
for(inti=1;i<=j;i++){
sum=sum+Math.pow(-1,i+1)/(2*i-1);
}
m=4*sum;
System.out.println(j+"\t\t"+m);
}
}
}
6.18检测密码
publicclassPass{
publicstaticvoidmain(String[]args){
Scannerin=newScanner(System.in);
System.out.print("请输入密码:
");
Stringstr=in.next();
password(str);
}
publicstaticvoidpassword(Stringstr){
booleana=str.matches("[A-Za-z0-9]{8,}");
intnum=0;
for(inti=0;icharch=str.charAt(i);
if(ch>='0'&&ch<='9'){num++;}
}
if(a&&num>2){System.out.println("密码正确");
}elseSystem.out.print("密码错误");
}
}
6.30游戏:
双骰子游戏
publicclassAce{
publicstaticvoidmain(String[]args){
intsum=random();
rusult(sum);
}
publicstaticintrandom(){
inta=(int)(Math.random()*6+1);
intb=(int)(Math.random()*6+1);
intsum=a+b;
System.out.println(a+"+"+b+"="+sum);
returnsum;
}
publicstaticvoidrusult(intsum){
if(sum==2||sum==3||sum==12){
System.out.println("你输了");
}elseif(sum==7||sum==11){
System.out.println("你赢了");
}elsecompare(sum);
}
publicstaticvoidcompare(intsum){
inta=sum;
intb=0;
System.out.println("确定的点数为:
"+a+"开始继续掷骰子");while(a!
=b||b!
=7){
b=random();
if(a==b){
System.out.println("你赢了");
break;
}elseif(b==7){
System.out.println("你输了");
break;
}
}
}
}