英文名:Introduction to Java Programming and Data Structures, Comprehensive Version, 11th Edition
2.13
import java.util.Scanner;publicclassbook{publicstaticvoidmain(String[] args){
Scanner input =newScanner(System.in);
System.out.print("Enter the monthly saving amount:");double m = input.nextDouble();double sum =0.0;for(int i=0;i<6;i++)
sum =(m+sum)*(1+0.00417);
System.out.println("After the sixth month, the account value is $"+sum+".");}}
2.14
import java.util.Scanner;publicclassbook{publicstaticvoidmain(String[] args){
Scanner input =newScanner(System.in);
System.out.print("Enter weight in pounds:");double pounds = input.nextDouble();
System.out.print("Enter height in inches:");double inches = input.nextDouble();double bmi = pounds*0.4535927/(inches*inches*0.0254*0.0254);
System.out.println("BMI is "+bmi+".");}}
2.15
import java.util.Scanner;publicclassbook{publicstaticvoidmain(String[] args){
Scanner input =newScanner(System.in);
System.out.print("Enter x1 and y1:");double x1 = input.nextDouble();double y1 = input.nextDouble();
System.out.print("Enter x2 and y2:");double x2 = input.nextDouble();double y2 = input.nextDouble();double d = Math.pow((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1),0.5);
System.out.println("The distance between the two points is "+d+".");}}
2.16
import java.util.Scanner;publicclassbook{publicstaticvoidmain(String[] args){
Scanner input =newScanner(System.in);
System.out.print("Enter the length of the side:");double s = input.nextDouble();double a =3*Math.pow(3,0.5)/2*s*s;
System.out.println("The area of the hexagon is "+a+".");}}
2.17
import java.util.Scanner;publicclassbook{publicstaticvoidmain(String[] args){
Scanner input =newScanner(System.in);
System.out.print("Enter the temperature in Fahrenheit:");double ta = input.nextDouble();
System.out.print("Enter the wind speed (>=2) in miles per hour:");double v = input.nextDouble();double twc =35.74+0.6215*ta-35.75*Math.pow(v,0.16)+0.4275*ta*Math.pow(v,0.16);
System.out.println("The wind chill is "+twc);}}
2.18
publicclassbook{publicstaticvoidmain(String[] args){
System.out.println("a b pow(a,b)");for(int i =1;i <=5;i++)
System.out.println(i+" "+(i+1)+" "+(int)Math.pow(i,i+1));}}
2.19
import java.util.Scanner;publicclassbook{publicstaticvoidmain(String[] args){
Scanner input =newScanner(System.in);
System.out.println("Enter the coordinates of three points separated by spaces");
System.out.print("like x1 y1 x2 y2 x3 y3:");double x1 = input.nextDouble();double y1 = input.nextDouble();double x2 = input.nextDouble();double y2 = input.nextDouble();double x3 = input.nextDouble();double y3 = input.nextDouble();double s1 = Math.pow((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2),0.5);double s2 = Math.pow((x2-x3)*(x2-x3)+(y2-y3)*(y2-y3),0.5);double s3 = Math.pow((x1-x3)*(x1-x3)+(y1-y3)*(y1-y3),0.5);double s =(s1+s2+s3)/2;double a = Math.pow(s*(s-s1)*(s-s2)*(s-s3),0.5);
System.out.println("The area of the triangle is "+a);}}
import java.util.Scanner;publicclassbook{publicstaticvoidmain(String[] args){
Scanner input =newScanner(System.in);
System.out.print("Enter investment amount:");double amount = input.nextDouble();
System.out.print("Enter annual interest rate in percentage:");double ar = input.nextDouble();
System.out.print("Enter number of years:");int y = input.nextInt();double fv = amount*Math.pow(1+ar/1200,y*12);
System.out.println("Future value is $"+fv);}}