如何按数组中的变量（int - 最小到最大）对数组进行排序？

Question

我有 10 个这样的数组：

    #include <stdio.h>
#include <iostream>
#include <cstdlib>
#include <sstream>

using namespace std;

struct person
{
    int age, i;
    char name[20], dob[20], pob[20], gender[7];
};

int main ()
{
    int i = 0;
    person person[10];
    for (i; i<10; i++)
    {
        cout << "Please enter your name, date of birth, place of birth, gender, and age, separated by a space.\nFor example, John 1/15/1994 Maine Male 20: ";
        scanf("%s %s %s %s %d", &person[i].name, &person[i].dob, &person[i].pob, &person[i].gender, &person[i].age);
        printf("%s %s %s %s %d \n", &person[i].name, &person[i].dob, &person[i].pob, &person[i].gender, person[i].age);
    }
    sort(person)
    return 0;
}

如何按年龄对所有这些数组进行排序？年龄是一个整数，从最小到最大？谢谢。

Answer 1

创建一个 lambda 为

auto func = [](Person p1, Person p2)
{
   return p1.age1 < p2.age2;
}

使用std::sort 对项目进行排序

std::sort(person.begin(),person.end(),func);

希望对你有帮助

工作代码如下所示

#include <iostream>
#include <algorithm>
#include <array>

struct Person{
    std::string name_, dob_, pob_;
    char gender_;
    int age_;

    Person(std::string name,std::string dob, std::string pob,char gender,int age)
    :name_(name),dob_(dob),pob_(pob),gender_(gender),age_(age)
    {
    }

    void print() const
    {
        std::cout<<name_<<" , "<<dob_<<" , "<<pob_<<" , "<<gender_<<" , "<<age_<<'\n'; 
    }
};

int main()
{


    std::array<Person,10> arr{
        Person{"AA","12/12/12","BB",'M',24},
        Person{"AA","12/12/12","BB",'M',23},
        Person{"AA","12/12/12","BB",'M',22},
        Person{"AA","12/12/12","BB",'M',21},
        Person{"AA","12/12/12","BB",'M',20},
        Person{"AA","12/12/12","BB",'M',34},
        Person{"AA","12/12/12","BB",'M',33},
        Person{"AA","12/12/12","BB",'M',32},
        Person{"AA","12/12/12","BB",'M',31},
        Person{"AA","12/12/12","BB",'M',30}
    };
    auto func = [] (Person p1,Person p2)
    {
        return p1.age_ < p2.age_;
    };
    std::sort(arr.begin(),arr.end(),func);

    for(auto const & item:arr)
    {
        item.print();
    }
}

Answer 2

使用#include<algorithm> 附带的std::sort(begin, end, comparator) 函数并提供您的自定义比较器，在这种情况下为

bool comparator(Person i, Person j) {
     return i.age < j.age;
}

std::sort(&Person[0], &Person[len], comparator);
//better alternative
std::sort(std::begin(Person), std::end(Person), comparator);