C++程序代写实现HashSet class

C++程序代写实现HashSet class

专业程序代写（QQ：928900200）

Implement a HashSet class for elements of type string.
It has the following functions: 
bool add(const string &)
bool contains(const string &) const
int size() const
In this exercise, you need to implement some of the above functions, as well as several internal functoins: 
int find(const string & e) const
void resize(int capacity2)
bool contains(const string & e) const
Hint:
The function find(e) finds the first position starting from p=h%N, which is either empty or equal to e. That is, find(e) should look like the following: 
int find(const string & e) const {
int p = hashIndex(e);
while (true) {
if (…) return p;
p = (p + 1) % capacity;
}
}
EXAMPLE INPUT 
apple
orange
banana
apple
orange

apple
watermelonEXAMPLE OUTPUT 
3
true
false

主程序

#include <iostream> 
#include <string> 
using namespace std;

////////////////////////// 
// Interfaces 
//

template <typename E> 
class Set 
{ 
public: 
virtual bool add(const E &) = 0; 
virtual bool contains(const E &) const = 0; 
virtual int size() const = 0; 
};

template <typename E> 
class HashFunction 
{ 
public: 
virtual int getHashCode(const E & e) const = 0; 
};

///////////////////////// 
// hash-function 
//

class StringHashFunction : public HashFunction<string> 
{ 
public: 
int getHashCode(const string & text) const { 
int code = 0; 
for (int i = 0; i < text.size(); ++ i) { 
int code1 = text[i]; 
code1 = code1 « (i * 8 % 24); 
code = code ^ code1; 
} 
return code; 
} 
};

///////////////////////// 
// your class 
//

class HashSet : public Set<string> 
{ 
private:

const StringHashFunction hashFunction;

class Entry 
{ 
public: 
string element; 
bool isInUse;

Entry() { 
isInUse = false; 
} 
};

Entry * entries;

int capacity; 
int count;

void initialize(int capacity2) { 
count = 0; 
capacity = capacity2; 
entries = new Entry[capacity]; 
}

void assign(const HashSet & set2) { 
count = set2.count; 
capacity = set2.capacity; 
entries = new Entry[capacity]; 
for (int i = 0; i < capacity; ++ i) { 
entries[i] = set2.entries[i]; 
} 
}

public:

HashSet() { 
initialize(2); 
}

~HashSet() { 
delete [] entries; 
}

HashSet(const HashSet & set2) { 
assign(set2); 
}

HashSet & operator = (const HashSet & set2) { 
delete [] entries; 
assign(set2); 
return (*this); 
}

private:

int hashIndex(const string & e) const { 
int hashCode = hashFunction.getHashCode(e); 
return hashCode % capacity; 
}

int find(const string & e) const;

void resize(int capacity2);

public:

bool add(const string & e) { 
int index = find(e); 
if (entries[index].isInUse) { 
return false; 
} 
entries[index].element = e; 
entries[index].isInUse = true; 
++ count; 
if (count > capacity / 2) { 
resize(capacity * 2); 
} 
return true; 
}

bool contains(const string & e) const;

int size() const { 
return count; 
}

};

#include “source”

int main() { 
HashSet set; 
for (int i = 0; i < 5; ++ i) { 
string text; 
cin » text; 
set.add(text); 
} 
cout « set.size() « endl; 
for (int i = 0; i < 2; ++ i) { 
string text; 
cin » text; 
if (set.contains(text)) { 
cout « “true” « endl; 
} 
else { 
cout « “false” « endl; 
} 
}

}