CPP（二）再接再厉：STL容器类的使用

STL容器类的目的是提高工作效率，省去了我们自己建立代码库的麻烦。学习这些容器类的前提是了解基本数据结构及其相关算法。

下面是使用这些类的事例代码，以备忘。以f结尾的函数表示这是一个测试某个容器类的函数，在main中调用即可看到这个测试函数的效果。

// Test.cpp : 定义控制台应用程序的入口点。
//
#include <iostream>
#include <algorithm>
#include <functional>
using namespace std;


// double-ended queue
#include <deque>
void dqf(void){
	deque<int> dq;
	for (int i = 0; i < 10; ++i){
		dq.push_front(i + 4);
	}
	for (deque<int>::iterator iter = dq.begin(); iter != dq.end(); ++iter){
		cout << *iter << endl;
	}
	cout << hex << dq.max_size() << endl;
}

// map
#include <map>// multi map
void mapf(void){
	map<int, int> m;
	pair<int, int> p(5, 20);
	m.insert(p);
	p.first = 6;
	m.insert(p);
	for (map<int, int>::iterator iter = m.begin(); iter != m.end(); ++iter){
		cout << "map loop" << endl;
		pair<int, int> p = *iter;
		cout << "key:" << p.first << " value:" << p.second << endl;
	}
}
// multimap
void mmapf(void)
{
	multimap<int, int> mmp;
	pair<int, int> p(8, 9);
	mmp.insert(p);
	mmp.insert(p);
	for (multimap<int, int>::iterator iter = mmp.begin(); iter != mmp.end(); ++iter)
	{
		pair<int, int> result = *iter;
		cout << result.first << " " << result.second << endl;
	}
}

// bitset
#include <bitset>
void bitf(void){
	bitset<32> bits;
	for (int i = 0; i < 32; ++i){
		bits[i] = i % 2 == 1 ? true : false;
		cout << bits[i] << " ";
	}
	cout << endl;
}

// list
#include <list>
void listf(void){
	list<int> ls;
	for (int i = 0; i < 10; ++i){
		ls.push_back(i);
	}
	for (list<int>::iterator iter = ls.begin(); iter != ls.end(); ++iter){
		cout << *iter << " ";
	}
}

// stack
#include <stack>
void stkf(void)
{
	stack<int> stk;
	stk.push(88);
	stk.push(77);
	cout << stk.size() << endl;
	cout << stk.top() << endl;
	stk.pop();
	cout << stk.size() << endl;
	cout << stk.top() << endl;
}

// vector
#include <vector>
void vectorf(void)
{
	vector<int> v(3);
	for (int i = 0; i < 3; ++i)
	{
		v[i] = i + 4;
	}
	for (int i = 0; i < 3; ++i)
	{
		cout << v[i] << endl;
	}
	for (vector<int>::iterator iter = v.begin(); iter != v.end(); ++iter)
	{
		cout << *iter << endl;
	}
}

// queue
#include <queue>// priority queue
void queuef(void)
{
	queue<int> q;
	q.push(88);
	q.push(1314);
	q.push(520);
	cout << q.front() << endl;
	q.pop();
	cout << q.front() << endl;
}
// 下面使用priority queue对人按照年龄排序，年龄大的先出队列。
struct person
{
	int age;
	char name[2];
	person(int initAge)
	{
		age = initAge;
		strcpy_s(name, "x");
	}
};
struct compare
{
	bool operator()(const person& left, const person& right) const
	{
		return left.age < right.age;
	}
};
void pqPersonF(void)
{
typedef priority_queue<person, vector<person>, compare> PersonQueue;
	PersonQueue pqPerson;
	pqPerson.push(person(18));
	pqPerson.push(person(50));
	pqPerson.push(person(35));
	pqPerson.push(person(90));
	pqPerson.push(person(8));
	cout << pqPerson.top().age << endl;
	pqPerson.pop();
	cout << pqPerson.top().age << endl;
}
// 对内置类型使用priority queue
void pqf(void)
{
	priority_queue<int, vector<int>, greater<int>> pq;
	pq.push(88);
	pq.push(1314);
	pq.push(520);
	cout << pq.top() << endl;
	pq.pop();
	cout << pq.top() << endl;
}

// multiset
#include <set>
void msetf(void)
{
	multiset<int> ms;
	ms.insert(9);
	ms.insert(8);
	ms.insert(2);
	ms.insert(9);
	// 有序排列的！从小到大。
	for (multiset<int>::iterator iter = ms.begin(); iter != ms.end(); ++iter)
	{
		cout << *iter << endl;
	}
}
// set
void setf(void){
	set<int> s;
	for (int i = 5; i >= 0; --i)
	{
		s.insert(i);
	}
	s.erase(1);
	// 从小到大有序排列
	for (set<int>::iterator iter = s.begin(); iter != s.end(); ++iter){
		cout << "[1]" << *iter << endl;
	}
	set<int>::iterator resultIter = s.find(0);
	s.erase(resultIter);
	for (set<int>::iterator iter = s.begin(); iter != s.end(); ++iter){
		cout << "[2]" << *iter << endl;
	}
}

int main(){
	pqPersonF();
	return 0;
}