c++ binary_search 搜索自定义数据类型

Question

c++ binary_search 可以搜索自定义数据类型吗？
如果可以，帮我改改下面的代码

//void test02()
//{
//    vector<Person>v;
//    char nameSeed[3][2] = { "A","B","C" };
//    srand((unsigned int)time(NULL));
//
//    for (int i = 0; i < 3; i++)
//    {
//        int age = rand() % 100 + 1;
//        v.push_back(Person((const char*)nameSeed[i], age));
//    }
//    sort(v.begin(), v.end(), MyCompare());
//    for_each(v.begin(), v.end(), MyPrint()); cout << endl;
//
//
//    Person pp("B", 0);
//    int result = binary_search(v.begin(), v.end(), pp);
//    if (result == 1)
//    {
//        cout << "已找到" << endl;
//    }
//    else
//        cout << "未找到" << endl;
//}

Answer 1

正确答案

// ConsoleApplication2.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//严重性    代码    说明    项目    文件    行    禁止显示状态
#define _CRT_SECURE_NO_WARNINGS


#include <iostream>
using namespace std;
#include <algorithm>
#include<vector>
#include<string>
#include<ctime>
#include<cstring>
const int L = 10;
class Person
{
public:
    Person(string name, int age);
    ~Person();


    bool operator<(const Person& p)    //需要排序前提的算法一般需要重载<
    {
        //return this->m_Age < p.m_Age;
        char str1[L],str2[L];
        strcpy(str1, this->m_Name.c_str());
        strcpy(str2, p.m_Name.c_str());
        int ret = strcmp(str1,str2);
        if (ret == -1)
        {
            return 1;
        }
        else
            return 0;
    }

private:
    string m_Name;
    int m_Age;

    friend void test02();
    friend class MyPrint;
    friend class MyCompare;
    friend bool myCompare(const Person& p1, const Person& p2);
};

Person::Person(string name, int age)
{
    this->m_Name = name;
    this->m_Age = age;
}

Person::~Person()
{

}

class MyPrint
{
public:
    void operator()(const Person& p)
    {
        cout << "姓名" << p.m_Name << "年龄" << p.m_Age << endl;
    }
};

//仿函数排序
class MyCompare
{
public:
    bool operator()(const Person& p1, const Person& p2)
    {
        return p1.m_Name > p2.m_Name;
    }
};

//普通函数排序
bool myCompare(const Person& p1, const Person& p2)
{
    return p1.m_Name > p2.m_Name;
}


void test01()
{
    vector<int>v;
    for (int i = 0; i < 9; i++)
    {
        v.push_back(i);
    }

    int result = binary_search(v.begin(), v.end(), 6);
    if (result == 1)
    {
        cout << "已找到" << endl;
    }
    else
        cout << "未找到" << endl;
}


void test02()
{
    vector<Person>v;
    char nameSeed[3][2] = { "A","B","C" };
    srand((unsigned int)time(NULL));

    for (int i = 0; i < 3; i++)
    {
        int age = rand() % 100 + 1;
        v.push_back(Person((const char*)nameSeed[i], age));
    }
    sort(v.begin(), v.end(), MyCompare());//先排序 
    for_each(v.begin(), v.end(), MyPrint()); cout << endl;


    Person pp("B", 0);

    //1用仿函数
    //int result = binary_search(v.begin(), v.end(),pp, MyCompare());
    
    //2用普通函数
    //int result = binary_search(v.begin(), v.end(), pp,myCompare);

    //3用匿名函数
    int result = binary_search(v.begin(), v.end(), pp, [](const Person& p1, const Person& p2) {return p1.m_Name > p2.m_Name; });
    
    //4其他方法
    //auto it=std::find_if(v.begin(), v.end(), [&pp](const Person&p) {return p.m_Name == pp.m_Name; });

    //if (it!=v.end())
    //{
    //    cout << "已找到" << endl;
    //    cout << it->m_Name << "\t" << it->m_Age << endl;
    //}
    //else
    //cout << "未找到" << endl;

    if (result == 1)
    {
        cout << "已找到" << endl;
    }
    else
        cout << "未找到" << endl;
}

int main()
{
    //test01();
    test02();





}