字符串类HString实现
HString.h
HString.cpp
main.cpp
1 #ifndef HSTRING_H
2 #define HSTRING_H
3
4 #include <iostream>
5 using namespace std;
6
7 const int MAX_SIZE = 128;
8
9 class HString
10 {
11 public:
12 HString();
13 HString(const HString &str);
14 HString(const char *str);
15 ~HString(){ delete [] ch; }
16
17 bool empty() const{ return len == 0 ? true : false; }
18 int length() const { return len; }
19 void strClear(HString &str){ len = 0; ch[0] = '\0'; }
20 char *toArray() { return ch; }
21
22 char &operator[](int i) const;
23 bool operator!(){ return empty(); }
24 HString &operator=(const HString &str);
25 HString &operator+(const HString &str);
26 HString &operator+=(const HString &str);
27
28 HString ©(const HString &str);
29 int find(HString &pat);
30 int find(char *pa);
31
32 void print();
33
34
35
36 private:
37 char *ch;
38 int len;
39
40 };
41
42 #endif
2 #define HSTRING_H
3
4 #include <iostream>
5 using namespace std;
6
7 const int MAX_SIZE = 128;
8
9 class HString
10 {
11 public:
12 HString();
13 HString(const HString &str);
14 HString(const char *str);
15 ~HString(){ delete [] ch; }
16
17 bool empty() const{ return len == 0 ? true : false; }
18 int length() const { return len; }
19 void strClear(HString &str){ len = 0; ch[0] = '\0'; }
20 char *toArray() { return ch; }
21
22 char &operator[](int i) const;
23 bool operator!(){ return empty(); }
24 HString &operator=(const HString &str);
25 HString &operator+(const HString &str);
26 HString &operator+=(const HString &str);
27
28 HString ©(const HString &str);
29 int find(HString &pat);
30 int find(char *pa);
31
32 void print();
33
34
35
36 private:
37 char *ch;
38 int len;
39
40 };
41
42 #endif
HString.cpp
1 #include "HString.h"
2
3 HString::HString()
4 {
5 ch = new char[MAX_SIZE + 1];//tail is '\0'
6 if(ch == NULL)
7 {
8 cerr << "Allocation failed! \n";
9 exit(-1);
10 }
11
12 len = 0;
13 ch[0] = '\0';
14 }
15
16 HString::HString(const HString &str)
17 {
18 ch = new char[MAX_SIZE + 1];
19 if(ch == NULL)
20 {
21 cerr << "Allocation failed! \n";
22 exit(-1);
23 }
24
25 int i;
26 len = str.length();
27 for(i = 0; i < len; i++)
28 {
29 ch[i] = str[i];
30 }
31 ch[len] = '\0';
32 }
33
34 HString::HString(const char *str)
35 {
36 ch = new char[MAX_SIZE + 1];
37 if(ch == NULL)
38 {
39 cerr << "Allocation failed! \n";
40 exit(-1);
41 }
42
43 int i = 0;
44 while(str[i] != '\0')
45 {
46 i++;
47 }
48
49
50 len = i;
51
52 for(i = 0; i < len; i++)
53 {
54 ch[i] = str[i];
55 }
56 ch[len] = '\0';
57 }
58
59 void HString::print()
60 {
61 cout << len << " elements: ";
62 for(int i = 0; i < len; i++)
63 {
64 cout << ch[i] << " ";
65 }
66
67 cout << endl;
68 }
69
70
71 char &HString::operator[](int i) const
72 {
73 if(i < 0 || i > len)
74 {
75 cerr << "Invailed index! \n";
76 exit(-1);
77 }
78
79 return ch[i];
80 }
81
82 int HString::find(HString &pat)
83 {
84 char *pa = pat.toArray();
85
86 if(*pa == '\0' || empty())
87 {
88 cerr << "Src or pattern string NULL \n";
89 exit(-1);
90 }
91
92 int i = 0, j = 0;
93
94 while(i < len && j < pat.length())
95 {
96 if(ch[i] == pa[j])
97 {
98 i++;
99 j++;
100 }
101 else
102 {
103 i = i - j + 1;
104 j = 0;
105 }
106 //cout << i << ": " << ch[i] << " " << j << " " << pa[j] << endl;
107
108 }
109
110 if(j >= pat.length())
111 return i - j;
112 else
113 return -1;
114 }
115
116
117 int HString::find(char *pa)
118 {
119 HString pat(pa);
120 return find(pat);
121
122 }
123
124 HString &HString::operator=(const HString &str)
125 {
126 return this->copy(str);
127 }
128
129
130 HString &HString::operator+=(const HString &str)
131 {
132 if(str.empty())
133 return *this;
134
135 if(len + str.length() > MAX_SIZE)
136 {
137 cerr << "cancat string too long \n";
138 exit(-1);
139 }
140
141 for(int i = 0; i < str.length(); i++)
142 {
143 ch[len + i] = str[i];
144 }
145 ch[len + str.length()] = '\0';
146
147 len = len + str.length();
148
149 return *this;
150 }
151
152 HString &HString::operator+(const HString &str)
153 {
154 HString *newStr = new HString(*this);
155 (*newStr) += str;
156
157 return *newStr;
158 }
159
160 HString &HString::copy(const HString &str)
161 {
162 if(&str == this)
163 return *this;
164
165 delete [] ch;
166 ch = new char[MAX_SIZE + 1];
167 if(ch == NULL)
168 {
169 cerr << "Allocation failed \n";
170 exit(-1);
171 }
172
173 len = str.length();
174 for(int i = 0; i < len; i++)
175 {
176 ch[i] = str[i];
177 }
178
179 return *this;
180 }
181
182
2
3 HString::HString()
4 {
5 ch = new char[MAX_SIZE + 1];//tail is '\0'
6 if(ch == NULL)
7 {
8 cerr << "Allocation failed! \n";
9 exit(-1);
10 }
11
12 len = 0;
13 ch[0] = '\0';
14 }
15
16 HString::HString(const HString &str)
17 {
18 ch = new char[MAX_SIZE + 1];
19 if(ch == NULL)
20 {
21 cerr << "Allocation failed! \n";
22 exit(-1);
23 }
24
25 int i;
26 len = str.length();
27 for(i = 0; i < len; i++)
28 {
29 ch[i] = str[i];
30 }
31 ch[len] = '\0';
32 }
33
34 HString::HString(const char *str)
35 {
36 ch = new char[MAX_SIZE + 1];
37 if(ch == NULL)
38 {
39 cerr << "Allocation failed! \n";
40 exit(-1);
41 }
42
43 int i = 0;
44 while(str[i] != '\0')
45 {
46 i++;
47 }
48
49
50 len = i;
51
52 for(i = 0; i < len; i++)
53 {
54 ch[i] = str[i];
55 }
56 ch[len] = '\0';
57 }
58
59 void HString::print()
60 {
61 cout << len << " elements: ";
62 for(int i = 0; i < len; i++)
63 {
64 cout << ch[i] << " ";
65 }
66
67 cout << endl;
68 }
69
70
71 char &HString::operator[](int i) const
72 {
73 if(i < 0 || i > len)
74 {
75 cerr << "Invailed index! \n";
76 exit(-1);
77 }
78
79 return ch[i];
80 }
81
82 int HString::find(HString &pat)
83 {
84 char *pa = pat.toArray();
85
86 if(*pa == '\0' || empty())
87 {
88 cerr << "Src or pattern string NULL \n";
89 exit(-1);
90 }
91
92 int i = 0, j = 0;
93
94 while(i < len && j < pat.length())
95 {
96 if(ch[i] == pa[j])
97 {
98 i++;
99 j++;
100 }
101 else
102 {
103 i = i - j + 1;
104 j = 0;
105 }
106 //cout << i << ": " << ch[i] << " " << j << " " << pa[j] << endl;
107
108 }
109
110 if(j >= pat.length())
111 return i - j;
112 else
113 return -1;
114 }
115
116
117 int HString::find(char *pa)
118 {
119 HString pat(pa);
120 return find(pat);
121
122 }
123
124 HString &HString::operator=(const HString &str)
125 {
126 return this->copy(str);
127 }
128
129
130 HString &HString::operator+=(const HString &str)
131 {
132 if(str.empty())
133 return *this;
134
135 if(len + str.length() > MAX_SIZE)
136 {
137 cerr << "cancat string too long \n";
138 exit(-1);
139 }
140
141 for(int i = 0; i < str.length(); i++)
142 {
143 ch[len + i] = str[i];
144 }
145 ch[len + str.length()] = '\0';
146
147 len = len + str.length();
148
149 return *this;
150 }
151
152 HString &HString::operator+(const HString &str)
153 {
154 HString *newStr = new HString(*this);
155 (*newStr) += str;
156
157 return *newStr;
158 }
159
160 HString &HString::copy(const HString &str)
161 {
162 if(&str == this)
163 return *this;
164
165 delete [] ch;
166 ch = new char[MAX_SIZE + 1];
167 if(ch == NULL)
168 {
169 cerr << "Allocation failed \n";
170 exit(-1);
171 }
172
173 len = str.length();
174 for(int i = 0; i < len; i++)
175 {
176 ch[i] = str[i];
177 }
178
179 return *this;
180 }
181
182
main.cpp
1 #include <iostream>
2 #include "HString.h"
3 using namespace std;
4
5 int main()
6 {
7 HString str("abcdefe");
8 str.print();
9
10 HString pat("de");
11
12 pat.print();
13 cout << str.find(pat) << endl;
14 cout << str.find("cd") << endl;
15
16 // str = pat;
17 // str.print();
18
19 str += pat;
20 str.print();
21
22 HString ns;
23 ns = str + pat;
24 ns.print();
25
26
27 return 0;
28
29 }
2 #include "HString.h"
3 using namespace std;
4
5 int main()
6 {
7 HString str("abcdefe");
8 str.print();
9
10 HString pat("de");
11
12 pat.print();
13 cout << str.find(pat) << endl;
14 cout << str.find("cd") << endl;
15
16 // str = pat;
17 // str.print();
18
19 str += pat;
20 str.print();
21
22 HString ns;
23 ns = str + pat;
24 ns.print();
25
26
27 return 0;
28
29 }