1 vector容器
1.1 基本概念
1.1.1 定义
1.1.2 内部结构
1.2 操作
1.2.1 构造vector
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void myPrint(vector<int> v) {
for (vector<int>::iterator it = v.begin(); it != v.end(); it++) {
cout << *it << " ";
}
}
void test01() {
//默认构造
vector<int> v;
for (int i = 0; i < 10; i++) {
v.push_back(i);
}
myPrint(v);
cout << "默认构造" << endl;
//通过区间方式构造
vector<int> v2(v.begin(), v.end());
myPrint(v2);
cout << "通过区间方式构造" << endl;
//n个elem方式构造
vector<int> v3(5, 10);
myPrint(v3);
cout << "n个elem方式构造" << endl;
//拷贝方式构造
vector<int> v4(v3);
myPrint(v4);
cout << "拷贝方式构造" << endl;
}
int main() {
test01();
return 0;
}
0 1 2 3 4 5 6 7 8 9 默认构造
0 1 2 3 4 5 6 7 8 9 通过区间方式构造
10 10 10 10 10 n个elem方式构造
10 10 10 10 10 拷贝方式构造1.2.2 vector的赋值
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void myPrint(vector<int> v) {
for (vector<int>::iterator it = v.begin(); it != v.end(); it++) {
cout << *it << " ";
}
}
void test01() {
vector<int> v;
for (int i = 0; i < 10; i++) {
v.push_back(i);
}
//方式一：=
vector<int> v2;
v2 = v;
myPrint(v2);
cout << "方式一：=" << endl;
//方式二：assign
vector<int> v3;
v3.assign(v.begin() + 3, v.end());
myPrint(v3);
cout << "方式二：assign" << endl;
//方式三：n个elem方式赋值
vector<int> v4;
v4.assign(5, 10);
myPrint(v4);
cout << "方式三：n个elem方式赋值" << endl;
}
int main() {
test01();
return 0;
}
0 1 2 3 4 5 6 7 8 9 方式一：=
3 4 5 6 7 8 9 方式二：assign
10 10 10 10 10 方式三：n个elem方式赋值1.2.3 容量和大小
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void myPrint(vector<int> v) {
for (vector<int>::iterator it = v.begin(); it != v.end(); it++) {
cout << *it << " ";
}
}
void test01() {
vector<int> v;
for (int i = 0; i < 10; i++) {
v.push_back(i);
}
myPrint(v);
cout << endl;
if (v.empty()) {
cout << "v为空" << endl;
}
else {
cout << "v不为空" << endl;
cout << "v的容量为：" << v.capacity() << endl;
cout << "v中元素的个数为：" << v.size() << endl;
}
//重新指定大小
v.resize(15); //如果重新指定长度变长，默认用0填充
myPrint(v);
cout << endl;
v.resize(16, 20); //如果重新指定长度变长，用elem填充
myPrint(v);
cout << endl;
v.resize(5); //如果重新指定长度变短，末尾元素删除
myPrint(v);
cout << endl;
}
int main() {
test01();
return 0;
}
0 1 2 3 4 5 6 7 8 9
v不为空
v的容量为：13
v中元素的个数为：10
0 1 2 3 4 5 6 7 8 9 0 0 0 0 0
0 1 2 3 4 5 6 7 8 9 0 0 0 0 0 20
0 1 2 3 41.2.4 vector的插入和删除
#include <iostream>
#include <vector>
using namespace std;
void myPrint(vector<int> v) {
for (vector<int>::iterator it = v.begin(); it != v.end(); it++) {
cout << *it << " ";
}
}
void test01() {
vector<int> v;
//尾插
v.push_back(10);
v.push_back(20);
v.push_back(30);
v.push_back(40);
myPrint(v); //10 20 30 40
cout << endl;
//插入
v.insert(v.begin() + 1, 5);
myPrint(v); //10 5 20 30 40
cout << endl;
v.insert(v.begin() + 1, 5, 3);
myPrint(v); //10 3 3 3 3 3 5 20 30 40
cout << endl;
//尾删
v.pop_back();
myPrint(v); //10 3 3 3 3 3 5 20 30
cout << endl;
//删除指定位置
v.erase(v.begin() + 1);
myPrint(v); //10 3 3 3 3 5 20 30
cout << endl;
v.erase(v.begin() + 1, v.begin() + 5); //不包括end
myPrint(v); //10 5 20 30
cout << endl;
//清空
v.clear();
myPrint(v);
cout << endl;
}
int main() {
test01();
return 0;
}
10 20 30 40
10 5 20 30 40
10 3 3 3 3 3 5 20 30 40
10 3 3 3 3 3 5 20 30
10 3 3 3 3 5 20 30
10 5 20 30
1.2.5 vector数据存取
#include <iostream>
#include <vector>
using namespace std;
void test01() {
vector<int> v;
for (int i = 0; i < 10; i++) {
v.push_back(i);
}
//at方式访问
for (int i = 0; i < v.size(); i++) {
cout << v.at(i) << " ";
}
cout << endl;
cout << "at方式访问" << endl;
//[]方式访问
for (int i = 0; i < v.size(); i++) {
cout << v[i] << " ";
}
cout << endl;
cout << "[]方式访问" << endl;
cout << "容器中第一个元素是：" << v.front() << endl;
cout << "容器中最后一个元素是：" << v.back() << endl;
}
int main() {
test01();
return 0;
}
0 1 2 3 4 5 6 7 8 9
at方式访问
0 1 2 3 4 5 6 7 8 9
[]方式访问
容器中第一个元素是：0
容器中最后一个元素是：9
1.2.6 vector互换容器
#include <iostream>
#include <vector>
using namespace std;
void myPrint(vector<int> v) {
for (vector<int>::iterator it = v.begin(); it != v.end(); it++) {
cout << *it << " ";
}
}
void test01() {
vector<int> v;
vector<int> v1;
for (int i = 0; i < 10; i++) {
v.push_back(i);
v1.push_back(10 - i);
}
cout << "交换前" << endl;
myPrint(v);
cout << endl;
myPrint(v1);
cout << endl;
cout << "交换后" << endl;
v.swap(v1);
myPrint(v);
cout << endl;
myPrint(v1);
}
int main() {
test01();
return 0;
}
交换前
0 1 2 3 4 5 6 7 8 9
10 9 8 7 6 5 4 3 2 1
交换后
10 9 8 7 6 5 4 3 2 1
0 1 2 3 4 5 6 7 8 9 
#include <iostream>
#include <vector>
using namespace std;
void test01() {
vector<int> v;
for (int i = 0; i < 100000; i++) {
v.push_back(i);
}
cout << "v中元素的个数为：" << v.size() << endl;
cout << "v的容量为：" << v.capacity() << endl;
v.resize(3);
cout << "重新分配元素个数后" << endl;
cout << "v中元素的个数为：" << v.size() << endl;
cout << "v的容量为：" << v.capacity() << endl;
//巧用swap收缩内存
vector<int>(v).swap(v);
cout << "v中元素的个数为：" << v.size() << endl;
cout << "v的容量为：" << v.capacity() << endl;
}
int main() {
test01();
return 0;
}
v中元素的个数为：100000
v的容量为：138255
重新分配元素个数后
v中元素的个数为：3
v的容量为：138255
v中元素的个数为：3
v的容量为：31.2.7 vector预留空间
#include <iostream>
#include <vector>
using namespace std;
void test01() {
vector<int> v;
int* p = NULL;
int num = 0;
for (int i = 0; i < 100000; i++) {
v.push_back(i);
if (p != &v[0]) {
p = &v[0];
num += 1;
}
}
cout << "预留空间前开辟了内存次数为：" << num << endl;
}
void test02() {
vector<int> v;
v.reserve(10000);
int* p = NULL;
int num = 0;
for (int i = 0; i < 100000; i++) {
v.push_back(i);
if (p != &v[0]) {
p = &v[0];
num += 1;
}
}
cout << "预留空间后开辟了内存次数为：" << num << endl;
}
int main() {
test01();
test02();
return 0;
}
预留空间前开辟了内存次数为：30
预留空间后开辟了内存次数为：7
1.2.8 vector的遍历
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void myPrint(int val){
cout << val << endl;
}
void test01(){
//定义vector
vector<int> v;
//往容器中插入数据
v.push_back(10);
v.push_back(20);
v.push_back(30);
v.push_back(40);
//1遍历
//1.1 方式一while
//通过迭代器访问容器中的数据
vector<int>:: iterator itBegin = v.begin();//起始迭代器 指向容器中第一个元素
vector<int>:: iterator itEnd = v.end();//结束迭代器 指向容器中最后一个元素的下一个位置
while(itBegin != itEnd){
cout << *itBegin << endl;
itBegin ++;
}
cout << "方式一----------" << endl;
//1.2 方式二for
for(vector<int>:: iterator it = v.begin();it != v.end();it++){
cout << *it << endl;
}
cout << "方式二----------" << endl;
//1.3 方式三 利用STL提供遍历算法
for_each(v.begin(), v.end(), myPrint);
cout << "方式三----------" << endl;
}
int main() {
test01();
return 0;
}
10
20
30
40
方式一----------
10
20
30
40
方式二----------
10
20
30
40
方式三----------1.3 vector存放自定义数据类型
1.3.1 存放自定义数据类型Person
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;
class Person
{
public:
Person(string name, int age)
{
this->m_Name = name;
this->m_Age = age;
}
string m_Name;
int m_Age;
};
void myPrint(Person val){
cout << "姓名："<< val.m_Name << "年龄："<< val.m_Age <<endl;
}
void test01(){
//定义vector
vector<Person> v;
Person p1("aaa", 10);
Person p2("bbb", 20);
Person p3("ccc", 30);
Person p4("ddd", 40);
Person p5("eee", 50);
//往容器中插入数据
v.push_back(p1);
v.push_back(p2);
v.push_back(p3);
v.push_back(p4);
v.push_back(p5);
//1遍历
//1.1 方式一while
//通过迭代器访问容器中的数据
vector<Person>:: iterator itBegin = v.begin();
vector<Person>:: iterator itEnd = v.end();
while(itBegin != itEnd){
cout << "姓名："<< (*itBegin).m_Name << "年龄："<< (*itBegin).m_Age <<endl;
itBegin++;
}
cout << "方式一----------" << endl;
//1.2 方式二for
for(vector<Person>:: iterator it = v.begin(); it != v.end(); it++){
cout << "姓名："<< (*it).m_Name << "年龄："<< (*it).m_Age <<endl;
//与下行代码等价
//cout << "姓名："<< it->m_Name << "年龄："<< it->m_Age <<endl;
}
cout << "方式二----------" << endl;
//1.3 方式三 利用STL提供遍历算法
for_each(v.begin(), v.end(), myPrint);
cout << "方式三----------" << endl;
}
int main() {
test01();
return 0;
}
姓名：aaa年龄：10
姓名：bbb年龄：20
姓名：ccc年龄：30
姓名：ddd年龄：40
姓名：eee年龄：50
方式一----------
姓名：aaa年龄：10
姓名：bbb年龄：20
姓名：ccc年龄：30
姓名：ddd年龄：40
姓名：eee年龄：50
方式二----------
姓名：aaa年龄：10
姓名：bbb年龄：20
姓名：ccc年龄：30
姓名：ddd年龄：40
姓名：eee年龄：50
方式三----------for_each（在algorithm头文件中）的声明：
1.3.2 存放自定义数据类型Person指针
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;
class Person
{
public:
Person(string name, int age)
{
this->m_Name = name;
this->m_Age = age;
}
string m_Name;
int m_Age;
};
void myPrint(Person val){
cout << "姓名："<< val.m_Name << "年龄："<< val.m_Age <<endl;
}
void test01(){
//定义vector
vector<Person*> v;
Person p1("aaa", 10);
Person p2("bbb", 20);
Person p3("ccc", 30);
Person p4("ddd", 40);
Person p5("eee", 50);
//往容器中插入数据
v.push_back(&p1);
v.push_back(&p2);
v.push_back(&p3);
v.push_back(&p4);
v.push_back(&p5);
for(vector<Person*>:: iterator it = v.begin(); it != v.end(); it++){
cout << "姓名："<< (**it).m_Name << "年龄："<< (**it).m_Age <<endl;
}
}
int main() {
test01();
return 0;
}
姓名：aaa年龄：10
姓名：bbb年龄：20
姓名：ccc年龄：30
姓名：ddd年龄：40
姓名：eee年龄：501.3.3 vector嵌套vector
#include <iostream>
#include <vector>
using namespace std;
void test01(){
//定义vector
vector< vector<int> > v;
//创建小容器
vector<int> v1;
vector<int> v2;
vector<int> v3;
vector<int> v4;
//往小容器中插入数据
for(int i = 0;i < 4;i++){
v1.push_back(i + 1);
v2.push_back(i + 2);
v3.push_back(i + 3);
v4.push_back(i + 4);
}
//往大容器中插入数据
v.push_back(v1);
v.push_back(v2);
v.push_back(v3);
v.push_back(v4);
for(vector< vector<int> >:: iterator it = v.begin(); it != v.end(); it++){
for(vector<int>:: iterator vit = (*it).begin(); vit != (*it).end(); vit++){
cout << *vit << " ";
}
cout <<endl;
}
}
int main() {
test01();
return 0;
}
1 2 3 4
2 3 4 5
3 4 5 6
4 5 6 7 2 deque容器
2.1 基本概念
2.1.1 定义
2.1.2 内部结构
2.2 操作
2.2.1 构造deque
构造方法与vector完全相同
#include <iostream>
#include <deque>
using namespace std;
void myPrint(const deque<int>&d) {
for (deque<int>::const_iterator it = d.begin(); it != d.end(); it++) {
//*it = 100; 容器中的数据不可以修改了
cout << *it << " ";
}
}
void test01() {
//默认构造
deque<int> d1;
for (int i = 0; i < 10; i++) {
d1.push_back(i);
}
myPrint(d1);
cout << "默认构造" << endl;
//通过区间方式构造
deque<int> d2(d1.begin(), d1.end());
myPrint(d2);
cout << "通过区间方式构造" << endl;
//n个elem方式构造
deque<int> d3(5, 10);
myPrint(d3);
cout << "n个elem方式构造" << endl;
//拷贝方式构造
deque<int> d4(d3);
myPrint(d4);
cout << "拷贝方式构造" << endl;
}
int main() {
test01();
return 0;
}
0 1 2 3 4 5 6 7 8 9 默认构造
0 1 2 3 4 5 6 7 8 9 通过区间方式构造
10 10 10 10 10 n个elem方式构造
10 10 10 10 10 拷贝方式构造2.2.2 deque的赋值
赋值方法与vector完全相同
#include <iostream>
#include <deque>
using namespace std;
void myPrint(const deque<int>&d) {
for (deque<int>::const_iterator it = d.begin(); it != d.end(); it++) {
cout << *it << " ";
}
}
void test01() {
deque<int> d1;
for (int i = 0; i < 10; i++) {
d1.push_back(i);
}
//方式一：=
deque<int> d2;
d2 = d1;
myPrint(d2);
cout << "方式一：=" << endl;
//方式二：assign
deque<int> d3;
d3.assign(d1.begin() + 3, d1.end());
myPrint(d3);
cout << "方式二：assign" << endl;
//方式三：n个elem方式赋值
deque<int> d4;
d4.assign(5, 10);
myPrint(d4);
cout << "方式三：n个elem方式赋值" << endl;
}
int main() {
test01();
return 0;
}
0 1 2 3 4 5 6 7 8 9 方式一：=
3 4 5 6 7 8 9 方式二：assign
10 10 10 10 10 方式三：n个elem方式赋值2.2.3 大小
deque无容量，其他的与vector完全相同
#include <iostream>
#include <deque>
using namespace std;
void myPrint(const deque<int>&d) {
for (deque<int>::const_iterator it = d.begin(); it != d.end(); it++) {
cout << *it << " ";
}
}
void test01() {
deque<int> d1;
for (int i = 0; i < 10; i++) {
d1.push_back(i);
}
myPrint(d1);
cout << endl;
if (d1.empty()) {
cout << "d1为空" << endl;
}
else {
cout << "d1不为空" << endl;
cout << "d1中元素的个数为：" << d1.size() << endl;
}
//重新指定大小
d1.resize(15); //如果重新指定长度变长，默认用0填充
myPrint(d1);
cout << endl;
d1.resize(16, 20); //如果重新指定长度变长，用elem填充
myPrint(d1);
cout << endl;
d1.resize(5); //如果重新指定长度变短，末尾元素删除
myPrint(d1);
cout << endl;
}
int main() {
test01();
return 0;
}
0 1 2 3 4 5 6 7 8 9
d1不为空
d1中元素的个数为：10
0 1 2 3 4 5 6 7 8 9 0 0 0 0 0
0 1 2 3 4 5 6 7 8 9 0 0 0 0 0 20
0 1 2 3 42.2.4 deque的插入和删除
deque比vector以下三个操作（红框标注）
#include <iostream>
#include <deque>
using namespace std;
void myPrint(const deque<int>& d) {
for (deque<int>::const_iterator it = d.begin(); it != d.end(); it++) {
cout << *it << " ";
}
}
void test01() {
deque<int> d1;
deque<int> d2(3,999);
//尾插
d1.push_back(10);
d1.push_back(20);
d1.push_back(30);
d1.push_back(40);
//头插
d1.push_front(100);
d1.push_front(200);
d1.push_front(300);
d1.push_front(400);
cout << "尾插后" << endl;
myPrint(d1); //400 300 200 100 10 20 30 40
cout << endl;
//插入
d1.insert(d1.begin() + 1, 5);
cout << "插入后" << endl;
myPrint(d1); //400 5 300 200 100 10 20 30 40
cout << endl;
d1.insert(d1.begin() + 1, 5, 3);
myPrint(d1); //400 3 3 3 3 3 5 300 200 100 10 20 30 40
cout << endl;
d1.insert(d1.begin(), d2.begin(), d2.end());
myPrint(d1); //999 999 999 400 3 3 3 3 3 5 300 200 100 10 20 30 40
cout << endl;
//尾删
d1.pop_back();
cout << "尾删后" << endl;
myPrint(d1); //999 999 999 400 3 3 3 3 3 5 300 200 100 10 20 30
cout << endl;
//头删
d1.pop_front();
cout << "头删后" << endl;
myPrint(d1); //999 999 400 3 3 3 3 3 5 300 200 100 10 20 30
cout << endl;
//删除指定位置
d1.erase(d1.begin() + 1);
cout << "删除指定位置后" << endl;
myPrint(d1); //999 400 3 3 3 3 3 5 300 200 100 10 20 30
cout << endl;
d1.erase(d1.begin() + 1, d1.begin() + 5); //不包括end
myPrint(d1); //999 3 3 5 300 200 100 10 20 30
cout << endl;
//清空
d1.clear();
cout << "清空后" << endl;
myPrint(d1);
cout << endl;
}
int main() {
test01();
return 0;
}
尾插后
400 300 200 100 10 20 30 40
插入后
400 5 300 200 100 10 20 30 40
400 3 3 3 3 3 5 300 200 100 10 20 30 40
999 999 999 400 3 3 3 3 3 5 300 200 100 10 20 30 40
尾删后
999 999 999 400 3 3 3 3 3 5 300 200 100 10 20 30
头删后
999 999 400 3 3 3 3 3 5 300 200 100 10 20 30
删除指定位置后
999 400 3 3 3 3 3 5 300 200 100 10 20 30
999 3 3 5 300 200 100 10 20 30
清空后2.2.5 deque数据存取
数据存取与vector完全相同
#include <iostream>
#include <deque>
using namespace std;
void myPrint(const deque<int>& d) {
for (deque<int>::const_iterator it = d.begin(); it != d.end(); it++) {
cout << *it << " ";
}
}
void test01() {
deque<int> d1;
for (int i = 0; i < 10; i++) {
d1.push_back(i);
}
//at方式访问
for (int i = 0; i < d1.size(); i++) {
cout << d1.at(i) << " ";
}
cout << "at方式访问" << endl;
//[]方式访问
for (int i = 0; i < d1.size(); i++) {
cout << d1[i] << " ";
}
cout << "[]方式访问" << endl;
cout << "容器中第一个元素是：" << d1.front() << endl;
cout << "容器中最后一个元素是：" << d1.back() << endl;
}
int main() {
test01();
return 0;
}
0 1 2 3 4 5 6 7 8 9 at方式访问
0 1 2 3 4 5 6 7 8 9 []方式访问
容器中第一个元素是：0
容器中最后一个元素是：92.2.6 deque排序
对于支持随机访问的迭代器的容器，都可以用sort方法直接对其进行排序
#include <iostream>
#include <deque>
#include <algorithm>
using namespace std;
void myPrint(const deque<int>& d) {
for (deque<int>::const_iterator it = d.begin(); it != d.end(); it++) {
cout << *it << " ";
}
}
void test01() {
deque<int> d1;
d1.push_back(10);
d1.push_back(20);
d1.push_back(30);
d1.push_back(40);
d1.push_front(100);
d1.push_front(200);
d1.push_front(300);
d1.push_front(400);
cout << "排序前" << endl;
myPrint(d1); //400 300 200 100 10 20 30 40
cout << endl;
//默认排序规则：从小到大
sort(d1.begin(), d1.end());
cout << "排序后" << endl;
myPrint(d1); //400 300 200 100 10 20 30 40
cout << endl;
}
int main() {
test01();
return 0;
}
排序前
400 300 200 100 10 20 30 40
排序后
10 20 30 40 100 200 300 400