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
151
152
|
class String{
struct Srep{
char *s;
int sz;
int n;
Srep(int nsz, const char *p)
{
n = 1;
sz = nsz;
s = new char[sz + 1];
strcpy(s, p);
}
~Srep()
{
delete[]s;
}
Srep *get_own_copy()
{
if (n == 1)
return this;
n--;
return new Srep(sz, s);
}
void assign(int nsz, const char *p)
{
if (sz != nsz){
delete []s;
sz = nsz;
s = new char[sz+1];
}
strcpy(s, p);
}
private:
Srep(const Srep &s);
Srep &operator=(const Srep &s);
};
Srep *rep;
public:
class Cref{ // reference to char
friend class String;
String &s;
int i;
Cref(String &ss, int ii):s(ss), i(ii){}
public:
operator char() { return s.Read(i);}
void operator=(char c){s.write(i, c);}
};
class Range{
char *s;
public:
Range(char *ss):s(ss){}
};
String()
{
rep = new Srep(0, "");
}
String(const char *s)
{
rep = new Srep(strlen(s), s);
}
String(const String &s)
{
s.rep->n++;
rep = s.rep; // Share representation
}
String &operator=(const char *s)
{
if (rep->n == 1)
rep->assign(strlen(s), s);
else {
rep->n--;
rep = new Srep(strlen(s), s);
};
return *this;
}
String &operator=(const String &s)
{
s.rep->n++;
if(--rep->n == 0)
delete rep;
rep = s.rep;
return *this;
}
~String()
{
if (--rep->n == 0)
delete rep;
}
void check(int i)const
{
if (i < 0 || rep->sz <= i)
throw Range("entered value is error");
}
char Read(int i)const
{
return rep->s[i];
}
void write(int i, char c)
{
rep = rep->get_own_copy(), rep->s[i] = c;
}
Cref operator[](int i)
{
check(i);
return Cref(*this, i);
}
char operator[](int i)const
{
check(i);
return rep->s[i];
}
//operator char*()const
//{
// return rep->s;
//}
// operator const char*()const
//{
// return rep->s;
//}
String &operator+=(const String &s1)
{
*this += s1.rep->s;
return *this;
}
String &operator +=(const char *s1)
{
*this->rep->s += *s1;
return *this;
}
};
|
