标签：系统 one == cout return play new mod col
由哈希表的定义，采用C++完成了一个学生成绩存储系统，分析过程如下：
由于哈希表是按KEY值存储，我们假设KEY值为一个字符串。hash算法为字符串的前两位大写字母所对应的数字对一个质数的模运算。
int Hash(KeyType c) { int n = c[0] - ‘A‘+c[1]-‘A‘+2; return n % Mod; }
哈希表的类定义如下
class HashTable { public: // HashTable(); HashTable(int len); ~HashTable(); bool SearchHash(KeyType K, int &p, int &c,int &s); bool InsertHash(ElemType e); private: ElemType * elem; int count; int sizeindex; };
搜索函数SearchHash
bool HashTable::SearchHash(KeyType K, int &p, int &c,int &s) { c = 0; p = Hash(K); std::string NULLKey = "None"; while (this->elem[p].key != NULLKey && K != this->elem[p].key) { p++; c++;//冲突次数++ } // cout << "after,p = " << p << endl; if (K == this->elem[p].key) { s = elem[p].score; return true; } else return false; }
插入函数InsertHash
bool HashTable::InsertHash(ElemType e) { int c = 0;//c为冲突次数 int p,s; if (SearchHash(e.key, p, c,s)) return false; else if (c < Hashsize[this->sizeindex] / 2) { this->elem[p] = e; this->count++; return true; } else { HashTable(); return false; } }
任务源代码如下：
哈希表元素类
1 //ElemType.h 2 3 #ifndef ELEMTYPE_H 4 #define ELEMTYPE_H 5 #include<string> 6 typedef std::string KeyType; 7 class ElemType 8 { 9 public: 10 KeyType key; 11 int score; 12 }; 13 #endif
哈希表类
1 //HashTable.h 2 3 #ifndef HASHTABLE_H 4 #define HASHTABLE_H 5 #include"ElemType.h" 6 7 class HashTable 8 { 9 public: 10 // HashTable(); 11 HashTable(int len); 12 ~HashTable(); 13 bool SearchHash(KeyType K, int &p, int &c,int &s); 14 bool InsertHash(ElemType e); 15 private: 16 ElemType * elem; 17 int count; 18 int sizeindex; 19 }; 20 21 22 #endif
哈希表的操作函数
1 //HashTable.cpp 2 3 #include"HashTable.h" 4 #include<iostream> 5 using namespace std; 6 const int Mod = 19;//质数模 7 int Hashsize[] = { 47,71,97,133 }; 8 int Hash(KeyType c) 9 { 10 int n = c[0] - ‘A‘+c[1]-‘A‘+2; 11 return n % Mod; 12 } 13 14 HashTable::HashTable(int len=20) 15 { 16 elem = new ElemType[len]; 17 for (int i = 0; i < len; i++) 18 { 19 elem[i].key = "None"; 20 } 21 count = 0; 22 sizeindex = 0; 23 } 24 25 HashTable::~HashTable() 26 { 27 delete[] elem; 28 count = 0; 29 sizeindex = 0; 30 } 31 32 bool HashTable::SearchHash(KeyType K, int &p, int &c,int &s) 33 { 34 c = 0; 35 p = Hash(K); 36 std::string NULLKey = "None"; 37 while (this->elem[p].key != NULLKey && K != this->elem[p].key) 38 { 39 p++; 40 c++;//冲突次数++ 41 } 42 // cout << "after,p = " << p << endl; 43 if (K == this->elem[p].key) 44 { 45 s = elem[p].score; 46 return true; 47 } 48 else 49 return false; 50 } 51 52 bool HashTable::InsertHash(ElemType e) 53 { 54 int c = 0;//c为冲突次数 55 int p,s; 56 if (SearchHash(e.key, p, c,s)) 57 return false; 58 else if (c < Hashsize[this->sizeindex] / 2) 59 { 60 this->elem[p] = e; 61 this->count++; 62 return true; 63 } 64 else 65 { 66 HashTable(); 67 return false; 68 } 69 }
信息存储的实现
1 //Main.cpp 2 3 #include"HashTable.h" 4 #include<iostream> 5 using namespace std; 6 int main() 7 { 8 HashTable* H = new HashTable(100); 9 ElemType e; 10 int p,c; 11 int i=1; 12 KeyType k; 13 int score; 14 while (i != 0) 15 { 16 switch (i) 17 { 18 case 1: 19 cout << "***______HashTable_____***" << endl; 20 cout << "***___1.Display menu___***" << endl; 21 cout << "***___2.Insert_________***" << endl; 22 cout << "***___3.Search_________***" << endl; 23 cout << "***___0.Exit___________***" << endl; 24 break; 25 case 2: 26 cout << "input name with A~Z: "; 27 cin >> k; 28 e.key = k; 29 cout << "input score with number: "; 30 cin >> score; 31 e.score = score; 32 H->InsertHash(e); 33 break; 34 case 3: 35 cout << "input name with A~Z: "; 36 cin >> k; 37 if (H->SearchHash(k, p, c, score)) 38 { 39 cout << k << "‘s score is " << score << endl;; 40 } 41 else 42 cout << "can‘t found" << endl; 43 break; 44 45 } 46 cout << "输入选项："; 47 cin >> i; 48 } 49 system("pause"); 50 return 0; 51 }
效果如下
***______HashTable_____*** ***___1.Display menu___*** ***___2.Insert_________*** ***___3.Search_________*** ***___0.Exit___________*** 输入选项：2 input name with A~Z: DSG input score with number: 99 输入选项：2 input name with A~Z: QWER input score with number: 70 输入选项：3 input name with A~Z: DSG DSG‘s score is 99 输入选项：2 input name with A~Z: OOP input score with number: 100 输入选项：3 input name with A~Z: QWER QWER‘s score is 70 输入选项：3 input name with A~Z: OOP OOP‘s score is 100 输入选项：0 请按任意键继续. . .
标签：系统 one == cout return play new mod col
原文地址：https://www.cnblogs.com/sgawscd/p/10087618.html
