? 书中第三章部分程序，加上自己补充的代码，包含公共符号表、集合类型
● 公共符号表，用于普通查找表的基本类
1 package package01;
2
3 import java.util.NoSuchElementException;
4 import java.util.TreeMap;
5 import edu.princeton.cs.algs4.StdIn;
6 import edu.princeton.cs.algs4.StdOut;
7
8 public class class01<Key extends Comparable<Key>, Value> implements Iterable<Key>
9 {
10 private TreeMap<Key, Value> st;
11
12 public class01()
13 {
14 st = new TreeMap<Key, Value>();
15 }
16
17 public Value get(Key key)
18 {
19 if (key == null)
20 throw new IllegalArgumentException("\n<get> key == null.\n");
21 return st.get(key);
22 }
23
24 public void put(Key key, Value val)
25 {
26 if (key == null)
27 throw new IllegalArgumentException("\n<put> key == null.\n");
28 if (val == null)
29 st.remove(key);
30 else
31 st.put(key, val);
32 }
33
34 public void delete(Key key)
35 {
36 if (key == null)
37 throw new IllegalArgumentException("\n<delete> key == null.\n");
38 st.remove(key);
39 }
40
41 public boolean contains(Key key)
42 {
43 if (key == null)
44 throw new IllegalArgumentException("\n<contains> key == null.\n");
45 return st.containsKey(key);
46 }
47
48 public int size()
49 {
50 return st.size();
51 }
52
53 public boolean isEmpty()
54 {
55 return size() == 0;
56 }
57
58 public Iterable<Key> keys()
59 {
60 return st.keySet();
61 }
62
63 public Key min()
64 {
65 if (isEmpty())
66 throw new NoSuchElementException("\n<min> empty.\n");
67 return st.firstKey();
68 }
69
70 public Key max()
71 {
72 if (isEmpty())
73 throw new NoSuchElementException("\n<max> empty.\n");
74 return st.lastKey();
75 }
76
77 public Key ceiling(Key key)
78 {
79 if (key == null)
80 throw new IllegalArgumentException("\n<min> key == null.\n");
81 Key k = st.ceilingKey(key);
82 if (k == null)
83 throw new NoSuchElementException("\n<min> k == null.\n");
84 return k;
85 }
86
87 public Key floor(Key key)
88 {
89 if (key == null)
90 throw new IllegalArgumentException("\n<min> key == null.\n");
91 Key k = st.floorKey(key);
92 if (k == null)
93 throw new NoSuchElementException("\n<min> k == null.\n");
94 return k;
95 }
96
97 public static void main(String[] args)
98 {
99 class01<String, Integer> st = new class01<String, Integer>();
100 for (int i = 0; !StdIn.isEmpty(); i++)
101 {
102 String key = StdIn.readString();
103 st.put(key, i);
104 }
105 for (String s : st.keys())
106 StdOut.println(s + " " + st.get(s));
107 }
108 }
● 集合类型
1 package package01;
2
3 import java.util.NoSuchElementException;
4 import java.util.Iterator;
5 import java.util.TreeSet;
6 import edu.princeton.cs.algs4.StdOut;
7
8 public class class01<Key extends Comparable<Key>> implements Iterable<Key>
9 {
10 private TreeSet<Key> set;
11
12 public class01()
13 {
14 set = new TreeSet<Key>();
15 }
16
17 public class01(class01<Key> x)
18 {
19 set = new TreeSet<Key>(x.set);
20 }
21
22 public void add(Key key)
23 {
24 if (key == null)
25 throw new IllegalArgumentException("\n<add> key == null.\n");
26 set.add(key);
27 }
28
29 public boolean contains(Key key)
30 {
31 if (key == null)
32 throw new IllegalArgumentException("\n<contains> key == null.\n");
33 return set.contains(key);
34 }
35
36 public void delete(Key key)
37 {
38 if (key == null)
39 throw new IllegalArgumentException("\n<delete> key == null.\n");
40 set.remove(key);
41 }
42
43 public int size()
44 {
45 return set.size();
46 }
47
48 public boolean isEmpty()
49 {
50 return size() == 0;
51 }
52
53 public Iterator<Key> iterator()
54 {
55 return set.iterator();
56 }
57
58 public Key max()
59 {
60 if (isEmpty())
61 throw new NoSuchElementException("\n<max> empty.\n");
62 return set.last();
63 }
64
65 public Key min()
66 {
67 if (isEmpty())
68 throw new NoSuchElementException("\n<min> key == null.\n");
69 return set.first();
70 }
71
72 public Key ceiling(Key key)
73 {
74 if (key == null)
75 throw new IllegalArgumentException("\n<ceiling> key == null.\n");
76 Key k = set.ceiling(key);
77 if (k == null)
78 throw new NoSuchElementException("\n<ceiling> k == null.\n");
79 return k;
80 }
81
82 public Key floor(Key key)
83 {
84 if (key == null)
85 throw new IllegalArgumentException("\n<floor> key == null.\n");
86 Key k = set.floor(key);
87 if (k == null)
88 throw new NoSuchElementException("\n<floor> k == null.\n");
89 return k;
90 }
91
92 public class01<Key> union(class01<Key> that)
93 {
94 if (that == null)
95 throw new IllegalArgumentException("\n<floor> key == null.\n");
96 class01<Key> c = new class01<Key>();
97 for (Key x : this)
98 c.add(x);
99 for (Key x : that)
100 c.add(x);
101 return c;
102 }
103
104 public class01<Key> intersects(class01<Key> that)
105 {
106 if (that == null)
107 throw new IllegalArgumentException("\n<floor> key == null.\n");
108 class01<Key> c = new class01<Key>();
109 if (this.size() < that.size()) // 遍历较小的集合，去较大的集合中匹配，无所谓？
110 {
111 for (Key x : this)
112 {
113 if (that.contains(x))
114 c.add(x);
115 }
116 }
117 else
118 {
119 for (Key x : that)
120 {
121 if (this.contains(x))
122 c.add(x);
123 }
124 }
125 return c;
126 }
127
128 public boolean equals(Object other)
129 {
130 if (other == this)
131 return true;
132 if (other == null)
133 return false;
134 if (other.getClass() != this.getClass())
135 return false;
136 class01 that = (class01) other;
137 return this.set.equals(that.set);
138 }
139
140 @Override
141 public int hashCode()
142 {
143 throw new UnsupportedOperationException("\n<hashCode> hashCode() not supported,\n");
144 }
145
146 @Override
147 public String toString() // 把集合的元素放进大括号中列出
148 {
149 String s = set.toString();
150 return "{ " + s.substring(1, s.length() - 1) + " }";
151 }
152
153 public static void main(String[] args)
154 {
155 class01<String> set = new class01<String>();
156 StdOut.println("set = " + set); // 输出空集合
157
158 set.add("www.cs.princeton.edu"); // 插入一些元素用于测试方法
159 set.add("www.cs.princeton.edu");
160 set.add("www.princeton.edu");
161 set.add("www.math.princeton.edu");
162 set.add("www.yale.edu");
163 set.add("www.amazon.com");
164 set.add("www.simpsons.com");
165 set.add("www.stanford.edu");
166 set.add("www.google.com");
167 set.add("www.ibm.com");
168 set.add("www.apple.com");
169 set.add("www.slashdot.com");
170 set.add("www.whitehouse.gov");
171 set.add("www.espn.com");
172 set.add("www.snopes.com");
173 set.add("www.movies.com");
174 set.add("www.cnn.com");
175 set.add("www.iitb.ac.in");
176
177 StdOut.println(set.contains("www.cs.princeton.edu"));
178 StdOut.println(!set.contains("www.harvardsucks.com"));
179 StdOut.println();
180 StdOut.println("ceiling(www.simpsonr.com) = " + set.ceiling("www.simpsonr.com"));
181 StdOut.println("ceiling(www.simpsons.com) = " + set.ceiling("www.simpsons.com"));
182 StdOut.println("floor(www.simpsonr.com) = " + set.floor("www.simpsonr.com"));
183 StdOut.println("floor(www.simpsons.com) = " + set.floor("www.simpsons.com"));
184 StdOut.println();
185 StdOut.println("set = " + set);
186 StdOut.println();
187 for (String s : set) // 直接列出表中元素
188 StdOut.println(s);
189 StdOut.println();
190 class01<String> set2 = new class01<String>(set);
191 StdOut.println(set.equals(set2));
192 }
193 }
原文地址：https://www.cnblogs.com/cuancuancuanhao/p/9795433.html
时间： 2024-10-13 02:45:30