如何对类数组进行排序 [英] How to sort a class array

问题描述

我正在尝试对其中具有5个值的类数组进行排序.3个字符串和2个 ints .我想在int值上从最高到最低对数组进行排序，但不知道该怎么做.我的流程虽然是将数组发送到类中，然后取出正​​确的int值并针对每个数组位置进行排序，但不更改该位置的其他值.如何提取这些值，以便对它们进行相应的排序?如果可以的话，我会知道如何完成我的代码.如果有更简单的方法可以做到这一点，那么我欢迎您提出任何建议.

I am trying to sort a class array that has 5 values inside of it. 3 strings and 2 ints. I would like to sort the array from highest to lowest on the int values but can't figure out how to do so. My though process is to send the array into the class and then pull out the correct int value and sort for each array location without changing the other values of that location. How can I pull out these values so that I can sort them accordingly? If I could then I would know how to finish my code. If there is an easier way to do this then I am open to any suggestions.

在下面的代码中，我有一个模板，该模板可以将数字取出来

In the code below I have a template of what I would do if I could pull that number out:

#include <iostream>
#include <string>
#include <iomanip>
using namespace std;

class Thing
{
public:
  Thing();
  void setvariables(string s, string g, string a, int y, int l);
  void get();
  void print();
  void sort_time(Thing data[], int datasize);

private:
  string name;
  string genre;
  string artist;
  int year;
  int length;
};

Thing::Thing()
{
  name = "";
  genre = "";
  artist = "";
  year = 13;
  length = 15;
}

void Thing::setvariables(string n, string g, string a, int y, int l)
{
  name = n;
  genre = g;
  artist = a;
  year = y;
  length = l;
}
/* void Thing::sort_time(Thing data[], int datasize)
{
int lar_pos, pos, lar_val;
for (int index = 0; index < datasize; index++)
{
    lar_pos = index;
    lar_val = data[index].get();
    for (pos = index; pos < datasize; pos++)
    {
        if (data[pos] > data[lar_pos])
        {
            lar_pos = pos;
            lar_val = data[lar_pos];
        }
    }
    data[lar_pos] = data[index];
    data[index] = lar_val;
}
}
void Thing::get()
{
l = length;
}
*/
void Thing ::print()
{
    cout << setw(25) << name << setw(10) << genre << setw(5) << year
    << setw(30) << artist << setw(5) << length << endl;
}

int main()
{
  // Create array of things
  int size = 9;
  Thing array[9];

  // Initialize array of things
  for (int i = 0; i<size; i++)
  {
    string name, genre, artist, junk;
    int year, length;

    getline(cin, name);
    getline(cin, genre);
    getline(cin, artist);
    cin >> year;
    cin >> length;
    array[i].setvariables(name, genre, artist, year, length);
    cin.ignore(256, '\n');
  }

  // Print array of things
  cout << setw(25) << "TITLE" << setw(10) << "GENRE" << setw(5) << "YEAR"
     << setw(30) << "ARTIST" << setw(5) << "TIME" << endl;
  cout << setw(25) << "=====" << setw(10) << "=====" << setw(5) << "===="
     << setw(30) << "======" << setw(5) << "====" << endl;
  for (int i = 0; i<size; i++)
    array[i].print();
  return 0;
}

推荐答案

使用 带有自定义比较器的std :: sort 或为您的类型定义 operator< .

示例:

#include <algorithm>

class Thing
{
  // ...
};

class ThingComparator
{
  bool operator()(const Thing& a, const Thing& b)
  {
    // Define your logic here and return true if a is considered lesser than b.
  }
};

int main()
{
  const int size = 9; // Make it constant!!
  Thing array[size];
  // Fill the array ...

  // Then sort it
  std::sort(array, array + size, ThingComparator()); 
}

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