MOOC清华《面向对象程序设计》第7章：统计考试及格率v5.4（单科及格与总分及格）

新需求：如何分别统计单科及格的人数和总分及格的人数？这种算法似乎在Microsoft Office. Excel中用得很多。视频中漏掉了一页课件，下载的PPT中有。

//main.cpp#include <iostream>#include <cstdlib>#include "ArrayCollection.h"#include "LinkedListCollection.h"#include "Score.h"#include "isPass.h"using namespace std;template <class _iterator, class _isPass>void analyze(_iterator begin, _iterator end, _isPass isPass){int passed = 0, count = 0;for(_iterator p = begin; p != end; p++){if(isPass(p))passed++;count++;}cout << "passing rate = " << (float)passed / count << endl;}int main(int argc, char** argv) {Score sarray[3];sarray[0] = Score(60, 60, 60);sarray[1] = Score(70, 70, 70);sarray[2] = Score(50, 80, 80);ArrayCollection<Score> collection3(3, sarray);LinkedListCollection<Score> collection4;for(int i = 0; i < 3; i++)collection4.addFirst(sarray[i]);analyze(sarray, sarray + 3, IsPass_ForEach<Score*, Score>(Score(70, 60, 60)));analyze(collection3.begin(), collection3.end(), IsPass_ForEach<Score*, Score>(Score(50, 60, 60)));analyze(collection4.begin(), collection4.end(), IsPass_ForEach<LinkedListIterator<Score>, Score>(Score(60, 60, 60)));cout << endl;analyze(sarray, sarray + 3, IsPass_Total<Score*, Score>(Score(70, 60, 60)));analyze(collection3.begin(), collection3.end(), IsPass_Total<Score*, Score>(Score(50, 60, 60)));analyze(collection4.begin(), collection4.end(), IsPass_Total<LinkedListIterator<Score>, Score>(Score(60, 60, 60)));system("PAUSE");return EXIT_SUCCESS;}

//Score.h#ifndef Score_h#define Score_h#include <iostream>using namespace std;struct Score{float value[3];Score(){}Score(float f1, float f2, float f3){value[0] = f1;value[1] = f2;value[2] = f3;}Score& operator=(const Score& s){value[0] = s.value[0];value[1] = s.value[1];value[2] = s.value[2];return *this;}bool operator>=(float pass){return (value[0] >= pass && value[1] >= pass && value[2] >= pass);}bool operator>=(Score pass){return (value[0] >= pass.value[0] && value[1] >= pass.value[1] && value[2] >= pass.value[2]);}float getTotal(){return value[0] + value[1] + value[2];}};ostream& operator<<(ostream& out, const Score& s){out << '{' << s.value[0] << ',' << s.value[1] << ',' << s.value[2] << '}';return out;}//注意这个流运算符重载不在类Score的内部定义，而要拿到外面来 #endif

//IsPass.h#ifndef IsPass_h#define IsPass_htemplate <class _iterator, class T>class IsPass_ForEach{T _pass;public:IsPass_ForEach(const T& pass):_pass(pass){}bool operator()(const _iterator& p){return (*p >= _pass);}};template <class _iterator, class T>class IsPass_Total{T _pass;public:IsPass_Total(const T& pass):_pass(pass){}bool operator()(const _iterator& p){return (p->getTotal() >= _pass.getTotal());}};#endif

//ArrayCollection.h#ifndef ArrayCollection_h#define ArrayCollection_htemplate <class T>class ArrayCollection{T* _data;int _size;public:ArrayCollection():_size(10){_data = new T[_size];}ArrayCollection(int size):_size(size){_data = new T[_size];}ArrayCollection(int size, T* data):_size(size){_data = new T[_size];for(int i = 0; i < size; i++)*(_data + i) = *(data + i);}~ArrayCollection(){delete[] _data;}T* begin(){return _data;}T* end(){return (_data + _size);}};#endif

//LinkedListCollection.h#ifndef LinkedListCollection_h#define LinkedListCollection_htemplate <class T>struct LinkedListNode{T _data;LinkedListNode *_next;LinkedListNode():_next(NULL){}LinkedListNode(T data):_data(data), _next(NULL){}LinkedListNode(T data, LinkedListNode<T>* next):_data(data), _next(next){}//注意上面这一行的第二个形参，其类型必须是LinkedListNode<T>*，否则//将与 LinkedListCollection::addFirst(T&) 中的_head的类型不匹配，编译器会报错！ };template <class T>struct LinkedListIterator{LinkedListNode<T> *pointer;LinkedListIterator(LinkedListNode<T> *p):pointer(p){}LinkedListIterator(const LinkedListIterator<T>& it):pointer(it.pointer){}LinkedListIterator<T>& operator++(){pointer = pointer->_next;return *this;}const LinkedListIterator<T> operator++(int){LinkedListIterator<T> temp = *this;pointer = pointer->_next;return temp;}T& operator*() const{return pointer->_data;}T* operator->() const{return &(pointer->_data);}bool operator!=(const LinkedListIterator<T> &other){return pointer != other.pointer;}bool operator==(const LinkedListIterator<T> &other){return pointer == other.pointer;}};template <class T>class LinkedListCollection{LinkedListNode<T>* _head;public:LinkedListCollection():_head(NULL){}~LinkedListCollection(){clear();}bool empty(){return (_head == NULL);}void addFirst(const T& data){_head = new LinkedListNode<T>(data, _head);}bool removeFirst(){if(_head != NULL){LinkedListNode<T>* p = _head;_head = _head->_next;delete p;return true;}else{return false;}}T* getFirst(){return (_head != NULL) ? &(_head->_data) : NULL;}LinkedListNode<T>* lastNode(){LinkedListNode<T>* p;for(p = _head; p->_next != NULL; p = p->_next) ;return p;}void addLast(const T& data){if(_head != NULL){lastNode()->_next = new LinkedListNode<T>(data);}else{_head = new LinkedListNode<T>(data);}}T* getLast(){return (_head != NULL) ? &(lastNode()->_data) : NULL;}bool removeLast(){if(_head != NULL){if(_head->_next != NULL){LinkedListNode<T>* p;for(p = _head; p->_next != NULL; p = p->_next) ;delete p->_next;p->_next = NULL;return true;}else{delete _head;_head = NULL;return true;}}elsereturn false;}void clear(){while(removeFirst()) ;}LinkedListIterator<T> begin(){return LinkedListIterator<T>(_head);}LinkedListIterator<T> end(){return LinkedListIterator<T>(NULL);}};#endif