every blog every motto: You will never know unless you try
0. Preface
For judging whether the specified element is summarized in the vector
1. Text
1.1 while
#include<iostream>
using namespace std;
#include<vector>
void test()
{
vector<int> v;
v.push_back(1);
v.push_back(2);
v.push_back(3);
vector<int>::iterator itBegin = v.begin(); // 起始迭代器
vector<int>::iterator itEnd = v.end(); // 结束迭代器
while (itBegin != itEnd)
{
cout << *itBegin << endl;
if (*itBegin == 2)
{
cout << "所查元素在其中" << endl;
break;
}
itBegin++;
}
}
int main() {
test();
system("pause");
}
1.2 for
#include<iostream>
using namespace std;
#include<vector>
void test()
{
vector<int> v;
v.push_back(1);
v.push_back(2);
v.push_back(3);
for (vector<int>::iterator it = v.begin(); it != v.end(); it++)
{
cout << *it << endl;
if (*it == 2)
{
cout << "所查元素在其中" << endl;
break;
}
}
}
int main() {
test();
system("pause");
}
1.3 find
1.3.1 Built-in data type search
#include<iostream>
using namespace std;
#include<algorithm>
#include<vector>
void test()
{
vector<int> v;
for (int i = 0; i < 10; i++)
{
v.push_back(i);
}
// 查找是否有5这个元素
vector<int>::iterator it;
it = find(v.begin(), v.end(), 5);
if (it == v.end())
cout << "没有找到指定元素" << endl;
else
cout << "找到指定元素" << endl;
}
int main() {
test();
system("pause");
}
1.3.1 Custom data type search
Need to reload "=="
Case number one:
#include<iostream>
using namespace std;
#include<vector>
#include<algorithm>
#include<string>
// 自定义数据类型查找
class Person
{
public:
Person(string name, int age)
{
this->m_Name = name;
this->m_Age = age;
}
// 重载==
bool operator==(const Person& p)
{
if (this->m_Name == p.m_Name&&this->m_Age == p.m_Age)
{
return true;
}
return false;
}
public:
string m_Name;
int m_Age;
};
void test022()
{
vector<Person> v;
// 创建数据
Person p1("aaa", 1);
Person p2("bbb", 2);
Person p3("ccc", 3);
Person p4("ddd", 4);
// 添加数据
v.push_back(p1);
v.push_back(p2);
v.push_back(p3);
v.push_back(p4);
vector<Person>::iterator it = find(v.begin(), v.end(), p2);
if (it == v.end())
{
cout << "没有找到" << endl;
}
else
{
cout << "找到姓名：" << it->m_Name << " 年龄: " << it->m_Age << endl;
}
}
int main()
{
test022();
system("pause");
}
Case 2:
#include<iostream>
using namespace std;
#include<vector>
#include<algorithm>
#include<string>
// 自定义数据类型查找
// 结构体
struct Point
{
int x;
int y;
// 重载==
bool operator==(const Point& p)
{
if (this->x== p.x&&this->y == p.y)
{
return true;
}
return false;
}
};
void test033()
{
Point point;
vector<Point>v; // 创建vector
for (int i = 0; i < 4; i++)
{
point.x = i;
point.y = i + 1;
v.push_back(point);
}
// find
Point p;
p.x = 1;
p.y = 1;
vector<Point>::iterator it = find(v.begin(), v.end(), p);
if (it == v.end())
{
cout << "没有找到" << endl;
}
else
{
cout << "找到了" << endl;
}
// 遍历打印输出
//for (vector<Point>::iterator it = v.begin(); it != v.end(); it++)
//{
// cout << "x:" << it->x << " y: " << it->y << endl;
//}
}
int main()
{
test033();
system("pause");
}