vector类的常用接口说明

目录

一、(constructor)构造函数声明

二、vector的迭代器

三、vector的增删改查

四、insert和erase，以及查找find（find不属于vector，是stl提供的算法）

五、三种遍历方式

六、源代码

---

vector是可变大小数组的序列容器

一、(constructor)构造函数声明

 

//构造
int TestVector1()
{
	//无参构造
	vector<int> v1;
	//构造并初始化n个val
	vector<int> v2(4, 100);
	//使用迭代器进行初始化构造
	vector<int> v3(v2.begin(), v2.end());
	//拷贝构造
	vector<int> v4(v3);
	return 0;
}

二、vector的迭代器

//迭代器
void PrintVector(const vector<int>& v)
{
	//遍历打印
	vector<int>::const_iterator it = v.begin();
	while (it != v.end())
	{
		cout << *it << " ";
		++it;
	}
	cout << endl;
}
void TestVector2()
{
	vector<int> v;
	v.push_back(1);
	v.push_back(2);
	v.push_back(3);
	v.push_back(4);
	//遍历打印
	vector<int>::iterator it = v.begin();
	while (it != v.end())
	{
		cout << *it << " ";
		++it;
	}
	cout << endl;
	//修改
	it = v.begin();
	while (it != v.end())
	{
		*it *= 2;
		++it;
	}
	//使用反向迭代器进行遍历再打印
	vector<int>::reverse_iterator rit = v.rbegin();
	while (rit != v.rend())
	{
		cout << *rit << " ";
		++rit;
	}
	cout << endl;
	PrintVector(v);
}

三、vector的增删改查

void TestVector4()
{
	vector<int> v;
	v.push_back(1);
	v.push_back(2);
	v.push_back(3);
	v.push_back(4);
	auto it = v.begin();
	while (it != v.end())
	{
		cout << *it << " ";
		++it;
	}
	cout << endl;
 
	v.pop_back();
	v.pop_back();
	it = v.begin();
	while (it != v.end())
	{
		cout << *it << " ";
		++it;
	}
	cout << endl;
}

四、insert和erase，以及查找find（find不属于vector，是stl提供的算法）

void TestVector5()
{
	vector<int> v{ 1,2,3,4 };
	auto pos = find(v.begin(), v.end(), 3);
	if (pos != v.end())
	{
		v.insert(pos, 30);
	}
	vector<int>::iterator it = v.begin();
	while (it != v.end())
	{
		cout << *it << " ";
		++it;
	}
	cout << endl;
	pos = find(v.begin(), v.end(), 3);
	// 删除pos位置的数据
	v.erase(pos);
 
	it = v.begin();
	while (it != v.end()) {
		cout << *it << " ";
		++it;
	}
	cout << endl;
 
}

五、三种遍历方式

void TestVector6()
{
	vector<int> v{ 1,2,3,4 };
	//通过[]读写第0个位置
	v[0] = 10;
	cout << v[0] << endl;
	//使用for+[]方式遍历
	for (size_t i = 0; i < v.size(); ++i)
	{
		cout << v[i] << " ";
	}
	cout << endl;
	vector<int> swapv;
	swapv.swap(v);
//使用迭代器遍历
	auto it = swapv.begin();
	while (it != swapv.end())
	{
		cout << *it << " ";
		++it;
	}
 
	// 3. 使用范围for遍历
	for (auto x : v)
		cout << x << " ";
	cout << endl;
}

六、源代码

#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
using namespace std;
#include<vector>
 
//构造
int TestVector1()
{
	//无参构造
	vector<int> v1;
	//构造并初始化n个val
	vector<int> v2(4, 100);
	//使用迭代器进行初始化构造
	vector<int> v3(v2.begin(), v2.end());
	//拷贝构造
	vector<int> v4(v3);
	return 0;
}
 
//迭代器
void PrintVector(const vector<int>& v)
{
	//遍历打印
	vector<int>::const_iterator it = v.begin();
	while (it != v.end())
	{
		cout << *it << " ";
		++it;
	}
	cout << endl;
}
void TestVector2()
{
	vector<int> v;
	v.push_back(1);
	v.push_back(2);
	v.push_back(3);
	v.push_back(4);
	//遍历打印
	vector<int>::iterator it = v.begin();
	while (it != v.end())
	{
		cout << *it << " ";
		++it;
	}
	cout << endl;
	//修改
	it = v.begin();
	while (it != v.end())
	{
		*it *= 2;
		++it;
	}
	//使用反向迭代器进行遍历再打印
	vector<int>::reverse_iterator rit = v.rbegin();
	while (rit != v.rend())
	{
		cout << *rit << " ";
		++rit;
	}
	cout << endl;
	PrintVector(v);
}
//尾插和尾删
void TestVector4()
{
	vector<int> v;
	v.push_back(1);
	v.push_back(2);
	v.push_back(3);
	v.push_back(4);
	auto it = v.begin();
	while (it != v.end())
	{
		cout << *it << " ";
		++it;
	}
	cout << endl;
 
	v.pop_back();
	v.pop_back();
	it = v.begin();
	while (it != v.end())
	{
		cout << *it << " ";
		++it;
	}
	cout << endl;
}
void TestVector5()
{
	vector<int> v{ 1,2,3,4 };
	auto pos = find(v.begin(), v.end(), 3);
	if (pos != v.end())
	{
		v.insert(pos, 30);
	}
	vector<int>::iterator it = v.begin();
	while (it != v.end())
	{
		cout << *it << " ";
		++it;
	}
	cout << endl;
	pos = find(v.begin(), v.end(), 3);
	// 删除pos位置的数据
	v.erase(pos);
 
	it = v.begin();
	while (it != v.end()) {
		cout << *it << " ";
		++it;
	}
	cout << endl;
 
}
void TestVector6()
{
	vector<int> v{ 1,2,3,4 };
	//通过[]读写第0个位置
	v[0] = 10;
	cout << v[0] << endl;
	//使用for+[]方式遍历
	for (size_t i = 0; i < v.size(); ++i)
	{
		cout << v[i] << " ";
	}
	cout << endl;
	vector<int> swapv;
	swapv.swap(v);
//使用迭代器遍历
	auto it = swapv.begin();
	while (it != swapv.end())
	{
		cout << *it << " ";
		++it;
	}
 
	// 3. 使用范围for遍历
	for (auto x : v)
		cout << x << " ";
	cout << endl;
}
int main()
{
	TestVector1();
	TestVector2();
	TestVector4();
	TestVector5();
	TestVector6();
 
	return 0;
}

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