forked from AllenDowney/ThinkJavaCode
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathSeries.java
More file actions
150 lines (123 loc) · 3.91 KB
/
Series.java
File metadata and controls
150 lines (123 loc) · 3.91 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
/**
* Examples from Chapter 6.
*/
public class Series {
public static void countup(int n) {
if (n == 0) {
System.out.println("Blastoff!");
} else {
countup(n - 1);
System.out.println(n);
}
}
public static double calculateArea(double radius) {
double result = Math.PI * radius * radius;
return result;
}
public static double calculateArea2(double radius) {
return Math.PI * radius * radius;
}
public static double absoluteValue(double x) {
if (x < 0) {
return -x;
} else {
return x;
}
}
public static double distance
(double x1, double y1, double x2, double y2) {
double dx = x2 - x1;
double dy = y2 - y1;
System.out.println("dx is " + dx);
System.out.println("dy is " + dy);
return 0.0;
}
public static double distance2
(double x1, double y1, double x2, double y2) {
double dx = x2 - x1;
double dy = y2 - y1;
double dsquared = dx * dx + dy * dy;
System.out.println("dsquared is " + dsquared);
return 0.0;
}
public static double distance3
(double x1, double y1, double x2, double y2) {
double dx = x2 - x1;
double dy = y2 - y1;
double dsquared = dx * dx + dy * dy;
double result = Math.sqrt(dsquared);
return result;
}
public static double circleArea
(double xc, double yc, double xp, double yp) {
double radius = distance(xc, yc, xp, yp);
double area = calculateArea(radius);
return area;
}
public static double calculateArea
(double xc, double yc, double xp, double yp) {
return calculateArea(distance(xc, yc, xp, yp));
}
/**
* Tests whether x is a single digit integer.
*
* @param x the integer to test
* @return true if x has one digit, false otherwise
*/
public static boolean isSingleDigit(int x) {
if (x > -10 && x < 10) {
return true;
} else {
return false;
}
}
public static boolean isSingleDigit2(int x) {
return x > -10 && x < 10;
}
public static int factorial(int n) {
if (n == 0) {
return 1;
}
int recurse = factorial(n - 1);
int result = n * recurse;
return result;
}
public static int fibonacci(int n) {
if (n == 1 || n == 2) {
return 1;
}
return fibonacci(n - 1) + fibonacci(n - 2);
}
public static void main(String[] args) {
countup(3);
System.out.println("Have a nice day.");
System.out.println("calculateArea");
System.out.println(calculateArea(3.0));
System.out.println("calculateArea2");
System.out.println(calculateArea2(3.0));
System.out.println("circleArea");
System.out.println(circleArea(1.0, 2.0, 4.0, 6.0));
System.out.println("calculateArea with 4 doubles");
System.out.println(calculateArea(1.0, 2.0, 4.0, 6.0));
System.out.println("absolute value");
System.out.println(absoluteValue(-2));
System.out.println("distance");
System.out.println(distance(1.0, 2.0, 4.0, 6.0));
System.out.println("distance2");
System.out.println(distance2(1.0, 2.0, 4.0, 6.0));
System.out.println("distance3");
System.out.println(distance3(1.0, 2.0, 4.0, 6.0));
System.out.println(isSingleDigit(2));
boolean bigFlag = !isSingleDigit2(17);
int z = 9;
if (isSingleDigit(z)) {
System.out.println("z is small");
} else {
System.out.println("z is big");
}
System.out.println("factorial");
System.out.println(factorial(3));
System.out.println("fibonacci");
System.out.println(fibonacci(3));
}
}