/* * vectorDemo.cpp * *  Created on: Jul 17, 2014 *      Author: lichfeng */#include<vector>#include <iostream.h>#include <algorithm>#include"vectorDemo.H"using namespace std;void vectorDemo() {	/**************************************************************************/	/*                    constructors functions                              */	/**************************************************************************/	vector<int> first;                               // empty vector of ints	vector<int> second(4, 100);                      // four ints with value 100	vector<int> third(second.begin(), second.end()); // iterating through second	vector<int> fourth(third);                       // a copy of third	// the iterator constructor can also be used to construct from arrays:	int myints[] = { 16, 2, 77, 29, 8, 3, 24 };	vector<int> fifth(myints, myints + sizeof(myints) / sizeof(int));	cout << "The contents of fifth are:";	for (vector<int>::iterator it = fifth.begin(); it != fifth.end(); ++it)		cout << ‘ ‘ << *it;	cout << ‘\n‘;	/**************************************************************************/	/* iterator erase (iterator position);                                    */	/* iterator erase (iterator first, iterator last);                        */	/* erase(): 在vector中移除一个元素（通过position），或者移除一个区间（[first, last)）内的元素*/	/*          该函数返回值是所删除的元素的下一个元素。                                    */	/* Note: 由于vector是以数组形式组织的，所以删除中间元素将导致vector中其他元素向前移动。这对vector  */	/*       而言是低效的操作，应减少使用。但此操作对list和deque等链表组织的容器很高效.              */	/**************************************************************************/	//vector<int>::iterator ii;	fifth.erase(fifth.begin() + 1);	cout << "After erase by position, the contents of fifth are:";	for (vector<int>::iterator it = fifth.begin(); it != fifth.end(); ++it)		cout << ‘ ‘ << *it;	cout << ‘\n‘;	fifth.erase(fifth.begin(), fifth.begin() + 2);	cout << "After erase by range, the contents of fifth are:";	for (vector<int>::iterator it = fifth.begin(); it != fifth.end(); ++it)		cout << ‘ ‘ << *it;	cout << ‘\n‘;	/***************************************************************************/	/* capacity(): 返回当前vector已分配的存储空间大小（按照所存元素类型），该值大于等于size（）                          */	/* size():     返回当前vector所实际存储的元素数目                                                                                                                             */	/* max_size(): 该vector可以分配的最大内存空间（操作系统限制的）                                                                                             */	/* push_back():在vector末尾增加一个元素，将导致size数加1。当且仅当size数大于当前容量时，                         */	/*             引起vector内存重新分配（按内存非配器算法增加vector容量                                                                      */	/* pop_back(): 移除vector的最后一个元素，引起size减少1                              */	/* begin():    返回指向vector第一个元素的iterator                                */	/* end():      返回指向vector最后一个元素的下一个元素的iterator， 不能取值。                                                     */	/* cbegin():   返回指向vector第一个元素的const iterator,不允许修改vector数据                                   */	/* cend():     返回指向vector最后一个元素的下一个元素的const iterator， 不能取值。                               */	/* at():       返回at(position)中position的引用.                              */	/* front():    返回vector第一個元素的引用.                                       */	/* back():     返回vector中最后一个元素的引用.                                    */	/* clear():    移除vector中所有的元素，将导致vector size为0.（capacity非强制变化）.     */	/**************************************************************************/	vector<int> vIntTest;	cout << "0：The size is " << vIntTest.size() << endl;	cout << "0:The capacity is " << vIntTest.capacity() << endl;	cout << "0:The max capacity is " << vIntTest.max_size() << endl;	for (int i = 0; i < 10; i++)		vIntTest.push_back(i);	cout << "1：The size is " << vIntTest.size() << endl;	cout << "1:The capacity is " << vIntTest.capacity() << endl;	vIntTest.pop_back();	cout << "2：The size is " << vIntTest.size() << endl;	cout << "2:The capacity is " << vIntTest.capacity() << endl;	vIntTest.insert(vIntTest.end(), 10, 100);	cout << "3：The size is " << vIntTest.size() << endl;	cout << "3:The capacity is " << vIntTest.capacity() << endl;	vIntTest.at(0) = 100;	vIntTest.at(1) = 200;	cout << "After set by at():";	for (vector<int>::iterator it = fifth.begin(); it != fifth.end(); ++it)		cout << ‘ ‘ << *it;	cout << ‘\n‘;	vIntTest.back() = 1000;	cout << "After set by back():";	for (vector<int>::iterator it = fifth.begin(); it != fifth.end(); ++it)		cout << ‘ ‘ << *it;	cout << ‘\n‘;	/***************************************************************************/	/* rbegin():   返回指向vector最后一个元素的迭代器，对翻转迭代器加操作将导致其向前移动.            */	/* empty():    判斷vector是否為空并返回，空返回true，非空返回false                      */	/* resize():   調整容器的size以包含n個元素，移除多餘的元素或增大內存空間                                                                            */	/* reserve():  要求vector capacity至少包含n個元素，如果n大于當前capacity，vector容量將增加  */	/***************************************************************************/	vector<int> reserveVec(5);	vector<int>::reverse_iterator ri;	int i=0;	for(ri=reserveVec.rbegin(); ri!=reserveVec.rend(); ri++)	{	    *ri = ++i;	}	cout<<"reserveVec contains: ";	for(vector<int>::iterator it= reserveVec.begin(); it != reserveVec.end(); it++)		cout<<"*it ";	cout<<endl;	/***************************************************************************/	/* data():     返回vector首元素的内部C类型指针，通过该指针完成所有的操作.                    */	/* empty():    判斷vector是否為空并返回，空返回true，非空返回false                      */	/* resize():   調整容器的size以包含n個元素，移除多餘的元素或增大內存空間                                                                            */	/* reserve():  要求vector capacity至少包含n個元素，如果n大于當前capacity，vector容量將增加  */	/***************************************************************************/	//data()    /*vector<int> myvector(5);	int* p = myvector.data();	*p = 10;	++p;	*p = 20;	p[2] = 100;	cout << "myvector contains:";	for (unsigned i = 0; i < myvector.size(); ++i)		cout << ‘ ‘ << myvector[i];	cout << ‘\n‘;*/	// reserve()	vector<int>::size_type sz;	vector<int> foo;	sz = foo.capacity();	std::cout << "making foo grow:\n";	for (int i = 0; i < 100; ++i) {		foo.push_back(i);		if (sz != foo.capacity()) {			sz = foo.capacity();			cout << "capacity changed: " << sz << ‘\n‘;		}	}	vector<int> bar;	sz = bar.capacity();	bar.reserve(100);   // this is the only difference with foo above	cout << "making bar grow:\n";	for (int i = 0; i < 100; ++i) {		bar.push_back(i);		if (sz != bar.capacity()) {			sz = bar.capacity();			cout << "capacity changed: " << sz << ‘\n‘;		}	}	//resize	vector<int> myvector1;	// set some initial content:	for (int i = 1; i < 10; i++)		myvector1.push_back(i);	myvector1.resize(5);	myvector1.resize(8, 100);	myvector1.resize(12);	cout << "myvector contains:";	for (int i = 0; i < myvector1.size(); i++)		cout << ‘ ‘ << myvector1[i];	cout << ‘\n‘;	//myvector contains: 1 2 3 4 5 100 100 100 0 0 0 0}