string容器
string构造函数
#include<iostream>
using namespace std;
#include<string.h>
void test01() {
string s1;//默认构造
const char* str = "hello world";
string s2(str);//传入char*
cout << "s2=" << s2 << endl;
string s3(s2);//传入string
cout << "s3=" << s3 << endl;
string s4(5, 'a');//5个a
cout << "s4=" << s4 << endl;
}
int main() {
test01();
return 0;
}赋值操作
#include<iostream>
using namespace std;
#include<string.h>
//赋值操作
void test() {
string str1;
str1 = "hello";//=赋值
cout << str1 << endl;
string str2;
str2 = str1;
cout << str2 << endl;
string str3;
str3 = 'a';//可以把单个字符赋值给字符串
cout << str3 << endl;
string str4;
str4.assign("hello c++");//assign赋值
cout << str4 << endl;
string str5;
str5.assign("study", 3);//把字符串的前3个字符赋值给str5
cout << str5 << endl;
string str6;
str6.assign(str5);
cout << str6 << endl;
string str7;
str7.assign(6, 'w');
cout << str7 << endl;
}
int main() {
test();
return 0;
}字符串拼接
字符串末尾追加字符串
#include<iostream>
using namespace std;
#include<string.h>
//字符串拼接
void test() {
string s1="hello";
s1 += " world";//追加字符串
cout << s1 << endl;
s1 += '!';//追加字符
cout << s1 << endl;
string s2 = " study";
s1 += s2;//追加字符串
cout << s1 << endl;
s1.append(" up up");
cout << s1 << endl;
s1.append(" eat food", 3);//把前n个字符拼接进来
cout << s1 << endl;
s1.append(s2);
cout << s1 << endl;
s1.append(s2, 0, 2);//从第0个位置截取2个字符，追加上
cout << s1 << endl;
}
int main() {
test();
return 0;
}string查找和替换
void test() {
string s1 = "abcdefgcd";
int pos = s1.find("cd");//3 返回d的位置。没有这个字串返回-1
if (pos == -1) {
cout << "未找到字符串" << endl;
}
else {
cout << pos << endl;//pos=2 position 位置
}
//rfind
//rfind从右往左查找，find从左往右查找
pos = s1.rfind("cd");//7
cout << pos << endl;
}
//替换
void test02() {
string s1 = "abcdefg";
s1.replace(1, 3, "1111");//从1号位置起 3个字符，替换成1111
cout << s1 << endl;//a1111efg
}string的字符串比较
void test() {
string s1 = "hello";
string s2 = "hello";
if (s1.compare(s2) == 0)
cout<<"相等" << endl;
else if(s1.compare(s2) > 0)
cout << "s1>s2" << endl;
else if(s1.compare(s2)<0)
cout << "s1<s2" << endl;
}string字符读取
void test() {
string s1 = "hello";
//cout << s1 << endl;
for (int i = 0; i < s1.size(); i++)
cout << s1[i] << " ";
cout << endl;
for (int i = 0; i < s1.size(); i++)
cout << s1.at(i) << " ";
s1[2] = 'a';//可以修改字符
s1.at(1) = 'b';
}string插入和删除
void test() {
string str = "hello";
str.insert(1, "111");//插入111
cout << str << endl;
str.erase(1, 3);//删除111.从1号位置删除3个字符
}string字串
从字符串中获取想要的字串
void test02() {
string email = "zhangsan@qq.com";
//从邮箱中获取用户名
int pos = email.find("@");
cout << email.substr(0, pos) << endl;
}vector
相似于数组，也称为单端数组。
和数组不同的是，vector可以动态扩展
#include<iostream>
using namespace std;
#include<vector>//vector头文件
//iterator迭代器
void printVector(vector<int>&v) {
for (vector<int>::iterator it = v.begin(); it != v.end(); it++)
cout << *it << " ";
cout << endl;
}
void test() {
vector<int>v1;//默认构造 无参构造
for (int i = 0; i < 10; i++)
v1.push_back(i);
printVector(v1);
//通过区间方式进行构造
vector<int>v2(v1.begin(), v1.end());
printVector(v2);
//n个 elem方式构造
vector<int>v3(3, 5);//3个5
printVector(v3);
//拷贝构造
vector<int>v4(v3);
printVector(v4);
}
int main() {
test();
return 0;
}vector赋值操作
void printVector(vector<int>& v) {
for (vector<int>::iterator it = v.begin(); it != v.end(); it++)
cout << *it << " ";
cout << endl;
}
void test() {
vector<int>v1;
for (int i = 0; i < 10; i++)
v1.push_back(i);
printVector(v1);
//operator= 赋值
vector <int>v2;
v2 = v1;
printVector(v2);
//assign
vector<int>v3;
v3.assign(v1.begin(), v1.end());
printVector(v3);
//n个 elem方式赋值
vector<int>v4;
v4.assign(5, 100);//5个100
printVector(v4);
}vector容器 容量和大小
#include<iostream>
using namespace std;
#include<vector>//vector头文件
void printVector(vector<int>& v) {
for (vector<int>::iterator it = v.begin(); it != v.end(); it++)
cout << *it << " ";
cout << endl;
}
void test() {
vector<int>v1;
for (int i = 0; i < 10; i++) {
v1.push_back(i);
}
printVector(v1);
if (v1.empty())
cout << "v1为空" << endl;
else {
cout << "v1不为空" << endl;
cout << v1.capacity() << endl;
cout << v1.size() << endl;
}
//重新指定大小
v1.resize(15,100);//指定用100填充 v1.resize(15);
printVector(v1);//如果重新指定的比原来长，默认用0填充
v1.resize(5);//指定的比原来短,超出的部分会删掉
printVector(v1);
}
int main() {
test();
return 0;
}插入和删除
void test() {
vector<int>v1;
//尾插
v1.push_back(10);
v1.push_back(20);
v1.push_back(30);
v1.push_back(40);
v1.push_back(50);
//遍历
printVector(v1);
//尾删
v1.pop_back();
printVector(v1);
//插入 第一个参数是迭代器
v1.insert(v1.begin(), 100);//起始迭代器
printVector(v1);
v1.insert(v1.begin(), 2, 1000);//在起始迭代器处插入2个1000
printVector(v1);
//删除
v1.erase(v1.begin());//在起始迭代器处删除
printVector(v1);
//清空
//v.clear();
v1.erase(v1.begin(), v1.end());//提供一个区间
printVector(v1);
}vector数据存取
void test() {
vector<int>v1;
for (int i = 0; i < 10; i++) {
v1.push_back(i);//尾插法
}
for (int i = 0; i < v1.size(); i++) {
cout << v1[i] << " ";
}
cout << endl;
for (int i = 0; i < v1.size(); i++)
cout << v1.at(i) << " ";
cout << endl;
//获取第一个元素
cout << v1.front() << endl;
//获取最后一个元素
cout << v1.back() << endl;
}vector互换容器
void test() {
vector<int>v;
int num = 0;//统计开辟次数
int* p = NULL;
for (int i = 0; i < 10000; i++) {
v.push_back(i);
if (p != &v[0]) {
p = &v[0];
num++;
}
}
cout << num << endl;
}deque容器
#include<iostream>
using namespace std;
#include<deque>
void printDeque(const deque<int>&d) {
for (deque<int>::const_iterator it = d.begin(); it != d.end(); it++)
cout << *it << " ";
cout << endl;
}
void test() {
deque<int>d1;
for (int i = 0; i < 10; i++)
{
d1.push_back(i);//插数
}
printDeque(d1);
deque<int>d2(d1.begin(), d1.end());
printDeque(d2);
deque<int>d3(5, 100);
printDeque(d3);
deque<int>d4(d3);
printDeque(d4);
}
int main() {
test();
return 0;
}赋值
void printDeque(const deque<int>&d) {//const使其只读
for (deque<int>::const_iterator it = d.begin(); it != d.end(); it++)
cout << *it << " ";
cout << endl;
}
void test() {
deque<int>d1;
for (int i = 0; i < 10; i++) {
d1.push_back(i);
}
printDeque(d1);
//operator= 赋值
deque<int>d2;
d2 = d1;
printDeque(d2);
//assign 赋值
deque<int>d3;
d3.assign(d1.begin(), d1.end());
printDeque(d3);
deque<int>d4;
d4.assign(5, 6);
printDeque(d4);
}deque容器大小
void test() {
deque<int>d1;
for (int i = 0; i < 10; i++)
d1.push_back(i);
if (d1.empty())
cout << "d1为空" << endl;
else {
cout << "d1不为空" << endl;
cout << d1.size() << endl;
//deque没有容量的概念，可以无限放
//重新指定大小
//d1.resize(15);
d1.resize(15, 3);//多的用3填充
printDeque(d1);
}
}deque容器的插入和删除
#include<iostream>
using namespace std;
#include<deque>
void printDeque(const deque<int>d) {//const防止误修改
for (deque<int>::const_iterator it = d.begin(); it != d.end(); it++)
cout << *it << " ";
cout << endl;
}
void test() {
deque<int>d1;
//尾插
d1.push_back(10);
d1.push_back(20);
//头插
d1.push_front(30);
d1.push_front(40);
printDeque(d1);//40 30 10 20
//尾删
d1.pop_back();
printDeque(d1);//40 30 10
//头删
d1.pop_front();
printDeque(d1);//30 10
}
void test02() {
deque<int>d1;
//尾插
d1.push_back(10);
d1.push_back(20);
//头插
d1.push_front(30);
d1.push_front(40);
printDeque(d1);//40 30 10 20
//insert插入
d1.insert(d1.begin(), 1000);
printDeque(d1);//1000 40 30 10 20
d1.insert(d1.begin(), 3, 9);
printDeque(d1);//9 9 9 1000 40 30 10 20
//删除指定位置
deque<int>::iterator it = d1.begin();
it+=5;
d1.erase(it);
printDeque(d1);//9 9 9 1000 40 10 20
//按照区间的形式删除
d1.erase(d1.begin(), it);//10 20
printDeque(d1);
//按照区间进行插入
deque<int>d2;
d2.push_back(1);
d2.push_back(2);
d2.push_back(3);
d1.insert(d1.begin(), d2.begin(), d2.end());
printDeque(d1);//1 2 3 10 20
//清空
d1.clear();
printDeque(d1);//只剩一个换行了
}
int main() {
test();
test02();
return 0;
}数据存取
void test() {
deque<int>d1;
d1.push_back(10);
d1.push_back(20);
d1.push_back(30);
d1.push_front(100);
d1.push_front(200);
d1.push_front(300);
//[]方式
for (int i = 0; i < d1.size(); i++)
cout << d1[i] << endl;
//at方式
for (int i = 0; i < d1.size(); i++)
cout << d1.at(i) << endl;
cout << "第一个元素：" << d1.front() << endl;
cout << "最后一个元素：" << d1.back() << endl;
}