Comparison function for priority queue Priority_queue

STL header files: #include <queue>

Priority queue:

Default from large to small arrange:priority_queuee<node>q;

Three ways to customize the priority:

1. Overloaded operators:

BOOL operator < (const node &a, const node &b)  {     return a.value < B.value;//Sort by value from large to small} priori ty_queue<node>q;

(const node &a is passed by reference, which is more efficient than passing node A by value, the effect is the same)

2. Custom comparison function template structure:

struct cmp{    bool operator () (const node &a, const node &b)    {        return a.value>b.value;// Sort by value from small to large    }};p Riority_queue<node, Vector<node>, cmp>q;

3. Define friend action class overloaded functions

struct node{    int value;    friend bool operator< (const node &a,const node &b) {        return a.value<b.value;  Arrange by value from large to small    }};p riority_queue<node>q;    

　　

Comparison function for priority queue Priority_queue