1 //统计元素个数
 2 
 3 #include<iostream>
 4 #include<string>
 5 #include<vector>
 6 #include<algorithm>
 7 using namespace std;
 8 
 9 //统计内置数据类型
10 void test01()
11 {
12     vector<int>v;
13 
14     v.push_back(10);
15     v.push_back(50);
16     v.push_back(90);
17     v.push_back(30);
18     v.push_back(30);
19     v.push_back(20);
20     v.push_back(30);
21 
22 
23     int num=count(v.begin(), v.end(), 30);
24     cout << "30的元素个数为: " << num << endl;
25 
26 }
27 
28 //统计自定义数据类型
29 class Person
30 {
31 public:
32     Person(string name, int age)
33     {
34         this->m_Name = name;
35         this->m_Age = age;
36     }
37 
38     bool operator==(const Person &p)
39     {
40         if (this->m_Age == p.m_Age)
41         {
42             return true;
43         }
44         else
45         {
46             return false;
47         }
48     }
49 
50     string m_Name;
51     int m_Age;
52 };
53 void test02()
54 {
55     vector <Person>v;
56     Person p1("张三", 30);
57     Person p2("李四", 40);
58     Person p3("王五", 30);
59     Person p4("赵六", 30);
60     Person p5("孙七", 70);
61 
62     v.push_back(p1);
63     v.push_back(p2);
64     v.push_back(p3);
65     v.push_back(p4);
66     v.push_back(p5);
67 
68 
69     Person p("齐吧", 30);
70     int num = count(v.begin(), v.end(), p);
71     cout << "和诸葛亮岁数一样的人为：" << num << endl;
72 }
73 
74 int main()
75 {
76 
77     test01();
78     test02();
79 
80     system("pause");
81     return 0;
82 }