JAVA语言程序设计(基础篇)原书第十版 梁勇著 第一章答案

第一章
1.1public class Test{
public static void main(String[]args){
System.out.println("Welcome to Java!");
System.out.println("Welcome to Computer Science!");
System.out.println("Programming is fun.");
}
}
1.2public class Test{
public static void main(String[]args){
for(int i=0;i<=4;i++){
System.out.println("Welcome to Java!");
}
}
}
1.3public class Test{
public static void main(String[]args){
System.out.println("]");
System.out.println("]");
System.out.println("]]");
System.out.println("]]");
}
}
public class Test{
public static void main(String[]args){
System.out.println("A");
System.out.println("A A");
System.out.println("AAAAA");
System.out.println("A A");
}
}
public class Test{
public static void main(String[]args){
System.out.println("V V");
System.out.println("V V");
System.out.println("V V");
System.out.println("V");
}
}
1.4public class Test{
public static void main(String[]args){
System.out.println("a a^2a^3");
System.out.println("111");
System.out.println("248");
System.out.println("3927");
System.out.println("41664");
}
}
1.5public class Test{
public static void main(String[]args){
System.out.println((9.5*4.5-2.5*3)/(45.5-3.5));
}
}
1.6public class Test{
public static void main(String[]args){
int i=1,sum=0;
for(;i<=9;i++)
sum+=i;
System.out.println(sum);
}
}
1.7public class Test{
public static void main(String[]args){
System.out.println(4*(1.0-1.0/3+1.0/5-1.0/7+1.0/9-1.0/11));
System.out.println(4*(1.0-1.0/3+1.0/5-1.0/7+1.0/9-1.0/11+1.0/13)) ;
}
}
1.8public class Test{
public static void main(String[]args){
final double PI=3.14;
double radius=5.5;
System.out.println(2*radius*PI);
System.out.println(PI*radius*radius);
}
}
1.9public class Test{
public static void main(String[]args){
System.out.println(7.9*4.5);
System.out.println(2*(7.9+4.5));
}
}
1.10public class Test{
public static void main(String[]args){
double S=14/1.6;
double T=45*60+30;
double speed=S/T;
System.out.println(speed);
}
}
1.11public class Test{
public static void main(String[]args){
int BN=312032486;//original person numbers
double EveryYS,EveryYBP,EveryYDP,EveryYMP;
EveryYS=365*24*60*60;
EveryYBP=EveryYS/7;
EveryYDP=EveryYS/13;
EveryYMP=EveryYS/45;
int FirstYP,SecondYP,ThirdYP,FourthYP,FivthYP;
FirstYP=(int)(BN+EveryYBP+EveryYMP-EveryYDP);
SecondYP=(int)(FirstYP+EveryYBP+EveryYMP-EveryYDP);
ThirdYP=(int)(SecondYP+EveryYBP+EveryYMP-EveryYDP);
FourthYP=(int)(ThirdYP+EveryYBP+EveryYMP-EveryYDP);
FivthYP=(int)(FourthYP+EveryYBP+EveryYMP-EveryYDP);
System.out.println(FirstYP);
System.out.println(SecondYP);
System.out.println(ThirdYP);
System.out.println(FourthYP);
System.out.println(FivthYP);
}
}
1.12public class Test{
public static void main(String[]args){
double S=24*1.6;
double T=(1*60+40)*60+35;
double speed=S/T;
System.out.println(speed);
}
}
1.13import java.util.Scanner;
public class Test{
public static void main(String[]args){
Scanner input=new Scanner(System.in);
System.out.println("input a,b,c,d,e,f value please:");
double a=input.nextDouble();
double b=input.nextDouble();
double c=input.nextDouble();
double d=input.nextDouble();
double e=input.nextDouble();
double f=input.nextDouble();
double x,y;
x=(e*d-b*f)/(a*d-b*c);
y=(a*f-e*c)/(a*d-b*c);
System.out.println("The result is x:"+(int)(x*1000)/1000.0);
System.out.println("The result is y:"+(int)(y*1000)/1000.0);
}
}。