我可以在自己的结构中使用向量排序 function 吗？ 总是编译器错误

Question

[Error] 'class std::vector' has no member named 'sort' which sort can use in struct and how to use? sorry for my bad english.

typedef struct name
{
    int x,y;
}name;

int main()
{
    int n,m,i;
    vector<name> a(10000);
    while(scanf("%d%d",&n,&m)!=EOF)
    {
        if(n==0&m==0)
        {
            break;
        }   
        a.clear();
        for(i=0;i<n;i++)
        {
            scanf("%d",&a[i].x);
            a[i].y=a[i].x%m;
        }
        a.sort();
        for(i=0;i<n;i++)
        {
            printf("%d\n",a[i].x);
        }
    }
    return 0;
}

Answer 1

vector doesn't have a sort function. Instead, use std::sort , and implement an operator< for your struct.

struct name
{
    int x,y;
    bool operator<( const name &other ) const {
        return x < other.x; // modify to whatever sorting conditions you need
    }
};

Then for calling sort, do

std::sort( a.begin(), a.end() );

Answer 2

Since std::vector has no sort() member function, you should use std::sort using the third argument as the sorting predicate. By doing so, you are not changing the internals of the struct you are sorting by adding an operator < :

#include <algorithm>
#include <vector>
struct name
{
    int x,y;
};

int main()
{
   std::vector<name> a(10000);

   // assuming you want to sort by x-coordinate  
   std::sort(a.begin(), a.end(), [](name& n1, name& n2) { return n1.x < n2.x; });
}

You can also create a separate lambda function:

#include <algorithm>
#include <vector>
struct name
{
    int x,y;
};

int main()
{
   std::vector<name> a(10000);
   auto comp = [](name& n1, name& n2) { return n1.x < n2.x; };

   // assuming you want to sort by x-coordinate  
   std::sort(a.begin(), a.end(), comp);
}