崔毅东 C++程序设计入门(下) 第10单元：月映千江未减明 – 模板 笔记

第01节：STL基础

#include <iostream>
#include <vector>
#include <list>
#include <deque>
#include <set>
#include <stack>
#include <queue>
using namespace std;

int main()
{
  vector<int> vector1, vector2;
  list<int> list1, list2;
  deque<int> deque1, deque2;
  set<int> set1, set2;
  multiset<int> multiset1, multiset2;
  stack<int> stack1, stack2;
  queue<int> queue1, queue2;

  cout << "Vector: " << endl;
  vector1.push_back(1);
  vector1.push_back(2);
  vector2.push_back(30);
  cout << "size of vector1: " << vector1.size() << endl;
  cout << "size of vector2: " << vector2.size() << endl;
  cout << "maximum size of vector1: " << vector1.max_size() << endl;
  cout << "maximum size of vector2: " << vector2.max_size() << endl;
  vector1.swap(vector2);
  cout << "size of vector1: " << vector1.size() << endl;
  cout << "size of vector2: " << vector2.size() << endl;
  cout << "vector1 < vector2? " << (vector1 < vector2)
    << endl << endl;

  cout << "List: " << endl;
  list1.push_back(1);
  list1.push_back(2);
  list2.push_back(30);
  cout << "size of list1: " << list1.size() << endl;
  cout << "size of list2: " << list2.size() << endl;
  cout << "maximum size of list1: " << list1.max_size() << endl;
  cout << "maximum size of list2: " << list2.max_size() << endl;
  list1.swap(list2);
  cout << "size of list1: " << list1.size() << endl;
  cout << "size of list2: " << list2.size() << endl;
  cout << "list1 < list2? " << (list1 < list2) << endl << endl;

  cout << "Deque: " << endl;
  deque1.push_back(1);
  deque1.push_back(2);
  deque2.push_back(30);
  cout << "size of deque1: " << deque1.size() << endl;
  cout << "size of deque2: " << deque2.size() << endl;
  cout << "maximum size of deque1: " << deque1.max_size() << endl;
  cout << "maximum size of deque2: " << deque2.max_size() << endl;
  deque1.swap(deque2);
  cout << "size of deque1: " << deque1.size() << endl;
  cout << "size of deque2: " << deque2.size() << endl;
  cout << "deque1 < deque2? " << (deque1 < deque2) << endl << endl;

  cout << "Set: " << endl;
  set1.insert(1);
  set1.insert(1);
  set1.insert(2);
  set2.insert(30);
  cout << "size of set1: " << set1.size() << endl;
  cout << "size of set2: " << set2.size() << endl;
  cout << "maximum size of set1: " << set1.max_size() << endl;
  cout << "maximum size of set2: " << set2.max_size() << endl;
  set1.swap(set2);
  cout << "size of set1: " << set1.size() << endl;
  cout << "size of set2: " << set2.size() << endl;
  cout << "set1 < set2? " << (set1 < set2) << endl << endl;

  cout << "Multiset: " << endl;
  multiset1.insert(1);
  multiset1.insert(1);
  multiset1.insert(2);
  multiset2.insert(30);
  cout << "size of multiset1: " << multiset1.size() << endl;
  cout << "size of multiset2: " << multiset2.size() << endl;
  cout << "maximum size of multiset1: " <<
        multiset1.max_size() << endl;
  cout << "maximum size of multiset2: " <<
        multiset2.max_size() << endl;
  multiset1.swap(multiset2);
  cout << "size of multiset1: " << multiset1.size() << endl;
  cout << "size of multiset2: " << multiset2.size() << endl;
  cout << "multiset1 < multiset2? " <<
        (multiset1 < multiset2) << endl << endl;

  cout << "Stack: " << endl;
  stack1.push(1);
  stack1.push(1);
  stack1.push(2);
  stack2.push(30);
  cout << "size of stack1: " << stack1.size() << endl;
  cout << "size of stack2: " << stack2.size() << endl;
  cout << "stack1 < stack2? " << (stack1 < stack2) << endl << endl;

  cout << "Queue: " << endl;
  queue1.push(1);
  queue1.push(1);
  queue1.push(2);
  queue2.push(30);
  cout << "size of queue1: " << queue1.size() << endl;
  cout << "size of queue2: " << queue2.size() << endl;
  cout << "queue1 < queue2? " << (queue1 < queue2) << endl << endl;

  return 0;
}

第03节：STL迭代器

#include <iostream>
#include <vector>
#include <set>
#include <algorithm>
using namespace std;

int main()
{
  vector<int> intVector;
  intVector.push_back(10);
  intVector.push_back(40);
  intVector.push_back(50);
  intVector.push_back(20);
  intVector.push_back(30);

  vector<int>::reverse_iterator p1;
  cout << "逆序遍历: ";
  for (p1 = intVector.rbegin(); p1 != intVector.rend(); p1++)
  {
    cout << *p1 << " ";
  }
  vector<int>::iterator p2;
  sort(intVector.rbegin(), intVector.rend());
  cout << "\n从大到小排序" << endl;
   for (p2 = intVector.begin(); p2 != intVector.end(); p2++)
  {
    cout << *p2 << " ";
  }

  set<int> intSet; //key
  intSet.insert(10);
  intSet.insert(40);
  intSet.insert(50);
  intSet.insert(20);
  intSet.insert(30);

  set<int>::iterator p3;
  cout << "\nTranverse the set: ";
  for (p3 = intSet.begin(); p3 != intSet.end(); p3++)
  {
    cout << *p3 << " ";
  }
  cout << endl;

  return 0;
}

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

int main()
{
  vector<int> intVector;
  intVector.push_back(10);
  intVector.push_back(20);
  intVector.push_back(30);
  intVector.push_back(40);
  intVector.push_back(50);
  intVector.push_back(60);

  vector<int>::iterator p1 = intVector.begin();
  for (; p1 != intVector.end(); p1++)
  {
    cout << *p1 << " ";
  }

  cout << endl << *(--p1) << endl;
  cout << *(p1 - 3) << endl;
  cout << p1[-3] << endl;
  *p1 = 1234;
  cout << *p1 << endl;

  return 0;
}

第04节：容器的更多用法

VectorDemo.cpp

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

int main()
{
  double values[] = {1, 2, 3, 4, 5, 6, 7};
  // 构造向量，用迭代器[beg, end)间的元素初始化向量 
  vector<double> doubleVector(values, values + 7);

  cout << "Initial contents in doubleVector: ";
  for (int i = 0; i < doubleVector.size(); i++)
    cout << doubleVector[i] << " ";

  // 顺序容器：assign(n, elem) 将n份元素拷贝赋值给容器 
  doubleVector.assign(4, 11.5);

  cout << "\nAfter the assign function, doubleVector: ";
  for (int i = 0; i < doubleVector.size(); i++)
    cout << doubleVector[i] << " ";

  // vector/deque中特有的函数at(index)返回指定位置的元素 
  doubleVector.at(0) = 22.4;
  cout << "\nAfter the at function, doubleVector: ";
  for (int i = 0; i < doubleVector.size(); i++)
    cout << doubleVector[i] << " ";

  // 定义迭代器，令其指向向量首位置 
  vector<double>::iterator itr = doubleVector.begin();
  // 顺序容器：insert(position, elem) 将元素插入指定位置 
  doubleVector.insert(itr + 1, 555);
  // !!!警告!!! 调用vector的insert之后，所有的迭代器都【可能】失效！ 
   //doubleVector.insert(itr + 1, 666);  // itr可能会失效
  itr = doubleVector.begin();
  doubleVector.insert(itr + 1, 666);
   
  cout << "\nAfter the insert function, doubleVector: ";
  for (int i = 0; i < doubleVector.size(); i++)
    cout << doubleVector[i] << " ";

  // 一级容器： erase(beg, end) 删除指定迭代器范围的元素 
  doubleVector.erase(itr + 2, itr + 4);
  //!!!警告!!! 调用vector的erase之后，beg及之后的迭代器都会失效！
   
  cout << "\nAfter the erase function, doubleVector: ";
  for (int i = 0; i < doubleVector.size(); i++)
    cout << doubleVector[i] << " ";

  doubleVector.clear();
  cout << "\nSize is " << doubleVector.size() << endl;
  cout << "Is empty? " <<
        (doubleVector.empty() ? "true" : "false") << endl;

  return 0;
}

ListDemo.cpp

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

int main()
{
  int values[] = {1, 2, 3, 4 };
  // 构造list，用迭代器[beg, end)间的元素初始化list 
  list<int> intList(values, values + 4);

  cout << "Initial contents in intList: ";
  list<int>::iterator p; // list的迭代器为双向迭代器 
  for (p = intList.begin(); p != intList.end(); p++)
    cout << *p << " ";

  // 顺序容器：assign(n, elem) 将n份元素拷贝赋值给容器 
  intList.assign(4, 11);
  cout << "\nAfter assign, intList: ";
  for (p = intList.begin(); p != intList.end(); p++)
    cout << *p << " ";

  list<int>::iterator itr = intList.begin();
  itr++;  // 迭代器指向第2个11：  11  ^11  11  11 
  // 顺序容器：insert(position, elem) 将元素插入指定位置 
  intList.insert(itr, 555); // 11  555  ^11  11  11 
  // 调用list的insert之后，迭代器不受影响，仍指向第2个11 
  intList.insert(itr, 666); // 11  555  666  ^11  11  11
  cout << "\nAfter insert, intList: ";
  for (p = intList.begin(); p != intList.end(); p++)
    cout << *p << " ";

  list<int>::iterator beg = intList.begin();
  itr++;
  // 一级容器： erase(beg, end) 删除指定迭代器范围的元素 
  intList.erase(beg, itr);
  // !!!警告!!! 被删除元素的迭代器均失效，其它元素迭代器仍有效 
  cout << "\nAfter erase, intList: ";
  for (p = intList.begin(); p != intList.end(); p++)
    cout << *p << " ";

  intList.clear();
  cout << "\nAfter clear, intList: ";
  cout << "Size is " << intList.size() << endl;
  cout << "Is empty? " <<
        (intList.empty() ? "true" : "false");

  // deque/list特有：push_front(elem)将元素插入列表首部 
  intList.push_front(10);
  intList.push_front(11);
  intList.push_front(12);
  cout << "\nAfter push, intList: ";
  for (p = intList.begin(); p != intList.end(); p++)
    cout << *p << " ";

  // deque/list特有：pop_front()删除列表首元素 
  intList.pop_front();
  // 顺序容器：pop_back()删除容器尾元素 
  intList.pop_back();
  cout << "\nAfter pop functions, intList: ";
  for (p = intList.begin(); p != intList.end(); p++)
    cout << *p << " ";

  int values1[] = {7, 3, 1, 2};
  list<int> list1(values1, values1 + 4);
  // list特有：sort() 将元素按升序排列 
  list1.sort();
  cout << "\nAfter sort, list1: ";
  for (p = list1.begin(); p != list1.end(); p++)
    cout << *p << " ";

  list<int> list2(list1);
  // list特有：merge(l2) 假定当前list与list2都已排序，
  //           将list2合并至本表，list2变空 
  list1.merge(list2);
  cout << "\nAfter merge, list1: ";
  for (p = list1.begin(); p != list1.end(); p++)
    cout << *p << " ";
  cout << "\nSize of list2 is " << list2.size();

  // list特有：reverse()反转本列表 
  list1.reverse();
  cout << "\nAfter reverse, list1: ";
  for (p = list1.begin(); p != list1.end(); p++)
    cout << *p << " ";

  list1.push_back(7);
  list1.push_back(1);
  cout << "\nAfter push, list1: ";
  for (p = list1.begin(); p != list1.end(); p++)
    cout << *p << " ";

  // list特有：remove(elem)删除表中与elem相等的元素 
  list1.remove(7);
  cout << "\nAfter remove, list1: ";
  for (p = list1.begin(); p != list1.end(); p++)
    cout << *p << " ";

  // 顺序容器：assign(n, elem) 将n份elem拷贝赋值给容器 
  list2.assign(7, 2);
  cout << "\nAfter assign, list2: ";
  for (p = list2.begin(); p != list2.end(); p++)
    cout << *p << " ";

  p = list2.begin();
  p++;
  // list特有：splice(pos,li)将li中所有元素移至本表pos位置之前
  //           然后li变空 
  list2.splice(p, list1);
  cout << "\nAfter splice, list2: ";
  for (p = list2.begin(); p != list2.end(); p++)
    cout << *p << " ";
  cout << "\nAfter splice, list1 size: "
    << list1.size();

  return 0;
}

ListDemo.cpp

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

int main()
{
  double values[] = {1, 2, 3, 4, 5, 6, 7};
  // 构造deque，用迭代器[beg, end)间的元素初始化deque  
  deque<double> doubleDeque(values, values + 7);

  cout << "Initial contents in doubleDeque: ";
  for (int i = 0; i < doubleDeque.size(); i++)
    cout << doubleDeque[i] << " ";

  // 顺序容器：assign(n, elem) 将n份元素拷贝赋值给容器 
  doubleDeque.assign(4, 11.5);
  cout << "\nAfter assign: ";
  for (int i = 0; i < doubleDeque.size(); i++)
    cout << doubleDeque[i] << " ";

  // deque/vector中特有：at(index)返回指定位置的元素 
  doubleDeque.at(0) = 22.4;
  cout << "\nAfter at: ";
  for (int i = 0; i < doubleDeque.size(); i++)
    cout << doubleDeque[i] << " ";

  deque<double>::iterator itr = doubleDeque.begin();
  // 顺序容器：insert(position, elem) 将元素插入指定位置 
  doubleDeque.insert(itr + 1, 555);
  // doubleDeque.insert(itr + 1, 666); // Error! Unexpected Behavior
  // !!!警告!!! 调用deque的insert之后，所有的迭代器都【必然】失效！
  //  
  itr = doubleDeque.begin(); // 重新获得迭代器 
  doubleDeque.insert(itr + 1, 666);
  
  cout << "\nAfter insert: ";
  for (int i = 0; i < doubleDeque.size(); i++)
    cout << doubleDeque[i] << " ";

  // 一级容器：erase(beg, end) 删除指定迭代器范围的元素
  doubleDeque.erase(itr + 2, itr + 4);
  // !!!警告!!! 调用deque的erase之后，所有的迭代器都【可能】失效！
  cout << "\nAfter erase: ";
  for (int i = 0; i < doubleDeque.size(); i++)
    cout << doubleDeque[i] << " ";

  doubleDeque.clear();
  cout << "\nAfter clear: ";
  cout << "Size is " << doubleDeque.size() << endl;
  cout << "Is empty? " <<
        (doubleDeque.empty() ? "true" : "false") << endl;

  // deque/list特有：push_front(elem)将元素压入队头 
  doubleDeque.push_front(10.10); // 10.10 
  doubleDeque.push_front(20.22); // 20.22 10.10
  doubleDeque.push_front(30.33); // 30.33 20.22 10.10
  cout << "After push_front: ";
  for (int i = 0; i < doubleDeque.size(); i++)
    cout << doubleDeque[i] << " ";

  // deque/list特有：pop_front()删除队首元素 
  doubleDeque.pop_front();
  // 顺序容器：pop_back()删除容器尾元素 
  doubleDeque.pop_back();
  cout << "\nAfter pop: ";
  for (int i = 0; i < doubleDeque.size(); i++)
    cout << doubleDeque[i] << " ";

  return 0;
}

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

int main()
{
  int values[] = {3, 5, 1, 7, 2, 2};
  // 构造multiset，用迭代器[beg, end)间的元素初始化deque 
  // 升序排列  1,2,2,3,5,7 
  multiset<int> set1(values, values + 6);
  // 降序排列  7,5,3,2,2,1
  //  multiset<int, greater<int> > set1(values, values + 6);
  
  cout << "Initial contents in set1: ";
  multiset<int>::iterator p;
  for (p = set1.begin(); p != set1.end(); p++) // set支持双向迭代器 
    cout << *p << " ";

  set1.insert(555); // 1,2,2,3,5,7,555 
  set1.insert(1);   // 1,1,2,2,3,5,7,555
  cout << "\nAfter insert, set1: ";
  for (p = set1.begin(); p != set1.end(); p++)
    cout << *p << " ";

  p = set1.lower_bound(2); // p指向容器中第一个2 
  cout << "\nValue of Lower bound of 2: " << *p;
  p = set1.upper_bound(2); // p指向容器中最后一个2的后面 
  cout << "\nValue of Upper bound of 2: " << *p;

  p = set1.find(2);
  if (p == set1.end()) // 若迭代器指向set尾部，则未找到 
    cout << "2 is not in set1" << endl;
  else
    cout << "\nThe number of 2: " << set1.count(2);

  set1.erase(2); // 将所有值为2的元素都删掉 
  cout << "\nAfter erase, set1: ";
  for (p = set1.begin(); p != set1.end(); p++)
    cout << *p << " ";

  return 0;
}

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

int main()
{
  map<int, string> map1;
  // 插入键值对 
  map1.insert(map<int, string>::value_type(100, "Zhang San"));
  map1.insert(map<int, string>::value_type(101, "Li Si"));
  map1.insert(map<int, string>::value_type(102, "Zhen Xiaosa"));
  map1.insert(map<int, string>::value_type(103, "Hao Meili"));

  cout << "Initial contents in map1:\n";
  map<int, string>::iterator p;
  for (p = map1.begin(); p != map1.end(); p++)
    cout << p->first << " " << p->second << endl;
    // 使用 first 访问 key； 使用 second 访问 value 
    
  cout << "Enter a key to serach for the name: ";
  int key;
  cin >> key;
  p = map1.find(key);

  if (p == map1.end()) // 若迭代器指向map尾部，则未找到指定键 
    cout << "  Key " << key << " not found in map1";
  else    
    cout << "  " << p->first << " " << p->second << endl;

  map1.erase(103);
  cout << "\nAfter erase 103, map1:\n";
  for (p = map1.begin(); p != map1.end(); p++)
    cout << p->first << " " << p->second << endl;

  return 0;
}

#include <iostream>
#include <queue>
#include <list>
using namespace std;

template<typename T>
void printQueue(T &queueRef)
{
  while (!queueRef.empty()) // 队列为空? 
  {
    cout << queueRef.front() << " "; // 读队头元素 
    queueRef.pop(); // 删除队头 
  }
}

int main()
{
  queue<int> queue1; // 基于deque实现 
  queue<int, list<int> > queue2; // 基于list实现 

  for (int i = 0; i < 8; i++)
  {                 // tail ...... head
    queue1.push(i); // 7,6,5,4,3,2,1,0
    queue2.push(i); // 7,6,5,4,3,2,1,0
  }

  cout << "Contents in queue1: ";
  printQueue(queue1);

  cout << "\nContents in queue2: ";
  printQueue(queue2);

  return 0;
}

#include <iostream>
#include <stack>
#include <vector>
using namespace std;

template<typename T>
void printStack(T &stackRef)
{
  while (!stackRef.empty())
  {
    cout << stackRef.top() << " ";
    stackRef.pop();
  }
}

int main()
{
  stack<int> stack1;
  stack<int, vector<int> > stack2;

  for (int i = 0; i < 8; i++)
  {
    stack1.push(i);
    stack2.push(i);
  }

  cout << "Contents in stack1: ";
  printStack(stack1);

  cout << "\nContents in stack2: ";
  printStack(stack2);

  return 0;
}