IntSLLNode.h#ifndef INT_SINGLY_LINKED_LIST_NODE #define INT_SINGLY_LINKED_LIST_NODE #include <iostream> using namespace std; class IntSLLNode { public: // 无参，一个参，二个参都有构造函数。 IntSLLNode() { info = 0; next = NULL; // 这是一个保险。啊 } IntSLLNode(int i, IntSLLNode* in = 0) { info = i; next = in; // 两个构造函数都将next置了0,太有用了 } friend class IntSLList; // very important, solve the problem of using private in other class or global function. friend istream& operator>>(istream&, IntSLList&); friend ostream& operator<<(ostream&, const IntSLList&); private: int info; IntSLLNode* next; }; #endif
IntSLList.h#ifndef INT_SINGLY_LINKED_LIST #define INT_SINGLY_LINKED_LIST #include "IntSLLNode.h" using namespace std; class IntSLList { public: IntSLList(); IntSLList(const int& n); IntSLList(istream &is); IntSLList(const IntSLList &object); ~IntSLList(); bool isEmpty() const; bool addToHead(int); bool addtoTail(int); bool deleteNode(const int&); int deleteFromHead(); int deleteFromTail(); bool isInList(const int&) const; IntSLLNode* getHead() const; IntSLLNode* getTail() const; friend ostream& operator<<(ostream&, const IntSLList&); friend istream& operator>>(istream&, IntSLList&); private: IntSLLNode *head; IntSLLNode *tail; }; #endif
IntSLList.cpp#include <iostream> #include "IntSLList.h" IntSLList::IntSLList() { head = NULL; // 指针一定要用空值来赋。 tail = NULL; } IntSLList::IntSLList(istream &is) { is >> *this; } IntSLList::IntSLList(const int& n) { head = new IntSLLNode; if (NULL == head) { return; } IntSLLNode *p1 = head; cout << "请输入第 1个节点的值" << endl; cin >> head->info; for (int i = 0; i < n - 1; i++) { IntSLLNode *p2 = new IntSLLNode; if (NULL == p2) { return; } cout << "请输入第 "<< i + 2 <<"个节点的值" << endl; cin >> p2->info; p1->next = p2; p1 = p2; } tail = p1; tail->next = NULL; // 两件事，1，把这里注释掉；2，将IntSLLNode里的next = 0 注释掉，自己看吧 } IntSLList::IntSLList(const IntSLList &object) {// 这一定不对啊，不能说是头尾相等，整个链表就相等啊，必须一个一个节点的赋值。 head = object.head; tail = object.tail; } IntSLList::~IntSLList() { for (IntSLLNode *p; !isEmpty(); ) { p = head->next; head = p; } } bool IntSLList::addToHead(int el) { head = new IntSLLNode(el, head); // 生成的新的头节点info为el，新生成的头节点next指向以前的head。 if (NULL == head) { return false; } if (NULL == tail) { tail = head; } return true; } bool IntSLList::addtoTail(int el) { if (tail != 0) { tail = tail->next = new IntSLLNode(el); } else { head = tail = new IntSLLNode(el); } return true; } int IntSLList::deleteFromHead() { int el = head->info; IntSLLNode *tmp = head; if (head == tail) { head = tail = NULL; } else { head = head->next; } return el; } int IntSLList::deleteFromTail() { int el = tail->info; if (head == tail) { head = tail = 0; } else { IntSLLNode *tmp; for (tmp = head; tmp->next != tail; tmp = tmp->next); tail = tmp; tail->next = 0; } return el; } bool IntSLList::deleteNode(const int& el) { if (head != NULL) { if ((head == tail) && (el == head->info)) { head = tail = NULL; return true; } else if (el == head->info) { IntSLLNode *tmp = head; head = head->next; return true; } else { IntSLLNode *pred = head; IntSLLNode *tmp = head->next; for (; (tmp != NULL) && (!(tmp->info == el)); pred = pred->next, tmp = tmp->next); if (tmp != NULL) { pred->next = tmp->next; // tmp指向的节点被删除。 if (tmp == tail) // 找到的节点是最后一个节点。 { tail = pred; // tail被赋值最后一个节点的地址。 } return true; } return false; } } else { return false; } } bool IntSLList::isInList(const int& el) const { IntSLLNode* tmp = head; for (; (tmp != NULL) && (!(tmp->info == el)); tmp = tmp->next); return tmp != NULL; } bool IntSLList::isEmpty() const { return NULL == head; } IntSLLNode* IntSLList::getHead() const { return head; } IntSLLNode* IntSLList::getTail() const { return tail; } /* ostream& operator<<(ostream &os, IntSLList &object) // 能用了，不过我把head与tail弄成public了 { // 我加一个成员函数用来返回头指针不就好了 for (IntSLLNode *p = object.head; p != NULL; p = p->next) // 试试看，呵呵 { os << p->info << " "; } return os; } */ ostream& operator<<(ostream &os, const IntSLList &object) { for (const IntSLLNode *p = object.getHead(); p != NULL; p = p->next) { os << p->info << " "; } return os; } // 这种情况现在是可以用了，我试着删掉一些东西看看。 // 这是在head,tail是public的情况下的 /*istream& operator>>(istream &is, IntSLList &object) // 我的这个程序有很多的地方要改，简直 { // 保留的地方少。 object.head = new IntSLLNode; cin >> object.head->info; IntSLLNode *p1 = object.head; int x; while (std::cin >> x) // 这个位置以前用字母来结束的时候会出问题 { // 现在没有了，可能是因为节点的构造函数每生成一个的时候都是指针域赋值0的。 IntSLLNode *p2 = new IntSLLNode; p2->info = x; p1->next = p2; p1 = p2; } // object.tail = p1; // 为什么注释了这个也可以，我要看看我的输出符 return is; // 我的输出符重载函数根本没有用到tail }*/ /* // 这个输入是head,tail,private的时候。 istream& operator>>(istream &is, IntSLList &object) { IntSLLNode *h = object.getHead(); // IntSLLNode *t = object.getTail(); 有用么，要设置它么？ IntSLLNode *p1 = h; p1 = new IntSLLNode; // 这里错的很可怕好好顺一顺，看看错的有多惨。 std::cin >> h->info; int x; while (std::cin >> x) { IntSLLNode *p2 = new IntSLLNode; p2->info = x; p1->next = p2; p1 = p2; } p1->next = 0; return is; }*/ /* // 我终于成功了 istream& operator>>(istream &is, IntSLList &object) { // 我想了很久实在想不出什么其它办法，只有填加一个设置头节点的函数了，试试看。 object.setHead(); IntSLLNode *h = object.getHead(); std::cin >> h->info; int x; while (std::cin >> x) { IntSLLNode *p2 = new IntSLLNode; if (NULL == p2) { return is; } p2->info = x; h->next = p2; h = p2; } return is; } */ /* 没有在类IntSLListNode中加 friend istream& operator>>(istream&, IntSLList&); istream& operator>>(istream &is, IntSLList &object) // I think this is better than the one above. { IntSLLNode* p = new IntSLLNode; p->info = 10; if (NULL == p) { return is; } object.head = p; int x; std::cin >> x; p->SetInfo(x); while (cin >> x) // whenever a wrong instream, quit loop { IntSLLNode *p2 = new IntSLLNode; if (NULL == p2) { return is; } p2->SetInfo(x); p->SetNext(p2); p = p2; } object.tail = p; return is; } */ istream& operator>>(istream &is, IntSLList &object) // I think this is better than the one above. { IntSLLNode* p = new IntSLLNode; if (NULL == p) { return is; } object.head = p; int x; cin >> x; p->info = x; while (cin >> x) // whenever a wrong instream, quit loop { IntSLLNode *p2 = new IntSLLNode; if (NULL == p2) { return is; } p2->info = x; // because the declaration in class IntSLLNode.h we can access the private member of IntSLLNode p->next = p2; p = p2; } object.tail = p; return is; }
