c++ - 如何为包含 int vector 的结构定义 less 运算符

Question

对于以下程序，我无法同步获得升序和降序。如您所见，输出的递增顺序和递减顺序并不相同。

程序:

#include <iostream>
#include <vector>
#include <algorithm>
#include<stdio.h>

using namespace std;

struct box{
    vector<int> dim;
    int index;
    box(vector<int> temp, int ind)
    {
        dim = temp;
        index = ind;
    }
    bool operator<(const box &rhs) const
    {
        for(int i = 0; i < dim.size(); i++)
        {
            if(dim[i] >= rhs.dim[i])
            {
                return false;
            }
        }
        return true;
    }

    void print()
    {
        for(int i = 0 ; i < dim.size(); i++)
        {
            cout<<dim[i]<<"\t";
        }
        cout<<endl;
    }
};

int main( )
{
    int n,k;

    while(scanf("%d %d", &k, &n) == 2){
        vector<box> arr;
        vector<box> newarr;
        for(int i = 0; i < k ; i++)
        {
            vector<int> temp;
            for(int j = 0; j < n ; j++)
            {
                int a;
                cin>>a;
                temp.push_back(a);
                std::sort(temp.begin(), temp.end());
            }
            arr.push_back(box(temp,i+1));
            newarr.push_back(box(temp,i+1));
        }

        std::sort(arr.begin(), arr.end());
        cout<<"Increasing Order"<<endl;
        for(int i  =0 ; i < k ; i++)
        {
            arr[i].print();
        }
        std::sort(newarr.rbegin(), newarr.rend());
        cout<<"Decreasing Order"<<endl;
        for(int i  =0 ; i < k ; i++)
        {
            newarr[i].print();
        }
    }

    return 0;
}

输入:

27 2
39 26
63 17
64 46
75 13
26 25
21 45
15 22
41 41
98 92
27 81
37 65
39 25
53 50
72 55
12 42
66 65
10 96
90 90
93 77
24 70
64 49
87 79
33 99
59 11
49 43
43 31
76 85

我的输出:

Increasing Order
12  42  
24  70  
25  39  
11  59  
15  22  
25  26  
21  45  
41  41  
31  43  
43  49  
37  65  
46  64  
50  53  
17  63  
26  39  
33  99  
49  64  
90  90  
77  93  
10  96  
65  66  
55  72  
13  75  
27  81  
76  85  
79  87  
92  98  
Decreasing Order
76  85  
33  99  
92  98  
79  87  
77  93  
90  90  
10  96  
65  66  
55  72  
27  81  
37  65  
50  53  
46  64  
49  64  
43  49  
41  41  
31  43  
26  39  
24  70  
17  63  
13  75  
11  59  
25  26  
21  45  
12  42  
25  39  
15  22

Answer 1

随便写

bool operator<(const box &rhs) const
{
    return dim < rhs.dim;
}