sort逆序实现的三种方式

法一：cmp函数

代码实现

#include<iostream>
#include<algorithm>

using namespace std;

int cmp(int a, int b)
{
    return a > b;
}

int main()
{
    int num[5] = {1, 2, 3, 4, 5};

    sort(num, num + 5, cmp);

    for ( int i = 0; i < 5; i ++ ) cout << num[i] << " ";
    cout << endl;

    return 0;
}

运行结果

法二：结构体重载大于号

注：需要将大于号重载给结构体中排序的关键变量

代码实现

#include<iostream>
#include<algorithm>

using namespace std;

struct Edge{
    int a, b;
    bool operator< (const Edge &W)const{
        return a > W.a;
    }
}edges[5];

int main()
{
    for ( int i = 0; i < 5; i ++ ) edges[i].a = edges[i].b = i + 1;

    sort(edges, edges + 5);

    for ( int i = 0; i < 5; i ++ ) cout << edges[i].a << " " << edges[i].b << endl;
    cout << endl;

    return 0;
}

运行结果

法三：greater<>()参数

#include<iostream>
#include<algorithm>

using namespace std;

int main()
{
    int num[5] = {1, 2, 3, 4, 5};

    sort(num, num + 5, greater<int>());

    for ( int i = 0; i < 5; i ++ ) cout << num[i] << " ";
    cout << endl;
    
    return 0;
}