C++ //常用查找算法 find //自定义类型需要重载 ==

  1 //常用查找算法  find
  2 #include<iostream>
  3 #include<algorithm>
  4 #include<functional>
  5 #include<vector>
  6 #include<string>
  7 #include<map>
  8
  9 using namespace std;
 10
 11 //内置数据类型
 12 void test01()
 13 {
 14     vector<int>v;
 15     v.push_back(10);
 16     v.push_back(20);
 17     v.push_back(30);
 18     v.push_back(40);
 19     v.push_back(50);
 20
 21     for (vector<int>::iterator it = v.begin(); it != v.end(); it++)
 22     {
 23         cout << *it << " ";
 24     }
 25     cout << endl;
 26     vector<int>::iterator findpos= find(v.begin(),v.end(),50);
 27
 28     if (findpos == v.end())
 29     {
 30         cout << "没有找到！" << endl;
 31
 32     }
 33     else
 34     {
 35         cout << "找到了" << endl;
 36         cout << *findpos << endl;
 37     }
 38
 39 }
 40
 41 class Person
 42 {
 43 public:
 44     Person(string name, int age)
 45     {
 46         this->m_Name = name;
 47         this->m_Age = age;
 48     }
 49     //重载 == 底层find知道如何对比Person数据类型
 50     bool operator==(const Person& p)
 51     {
 52         if (this->m_Name == p.m_Name && this->m_Age == p.m_Age)
 53         {
 54             return true;
 55         }
 56         else
 57         {
 58             return false;
 59         }
 60     }
 61
 62
 63     string m_Name;
 64     int m_Age;
 65 };
 66
 67
 68 //查找自定义 要重载
 69 void test02()
 70 {
 71     vector<Person>v2;
 72
 73
 74     Person p1("张三", 10);
 75     Person p2("李四", 20);
 76     Person p3("王五", 30);
 77     Person p4("赵六", 40);
 78
 79     v2.push_back(p1);
 80     v2.push_back(p2);
 81     v2.push_back(p3);
 82     v2.push_back(p4);
 83
 84     Person pp("李四",20);
 85
 86     vector<Person>::iterator it = find(v2.begin(), v2.end(), pp);
 87
 88
 89         if (it == v2.end())
 90         {
 91             cout << "没有找到！" << endl;
 92         }
 93         else
 94         {
 95             cout << "找到了！" << endl;
 96             cout << "姓名：" << it->m_Name << "\t年龄：" << it->m_Age << endl;
 97         }
 98
 99
100
101 }
102
103
104
105 int main()
106 {
107
108     test01();
109     test02();
110
111     system("pause");
112     return 0;
113 }