priority_queue调用 STL里面的 make_heap(), pop_heap(), push_heap() 算法实现,也算是堆的另外一种形式。先写一个用 STL 里面堆算法实现的与真正的STL里面的 priority_queue用法相似的priority_queue, 以加深对 priority_queue 的理解
#include <iostream>
#include <algorithm>
#include <vector>
using
namespace
std;
class
priority_queue
{
private
:
vector<
int
> data;
public
:
void
push(
int
t ){
data.push_back(t);
push_heap( data.begin(), data.end());
}
void
pop(){
pop_heap( data.begin(), data.end() );
data.pop_back();
}
int
top() {
return
data.front(); }
int
size() {
return
data.size(); }
bool
empty() {
return
data.empty(); }
};
int
main()
{
priority_queue test;
test.push( 3 );
test.push( 5 );
test.push( 2 );
test.push( 4 );
while
( !test.empty() ){
cout << test.top() << endl;
test.pop(); }
return
0;
}
|
#include <iostream>
#include <queue>
using
namespace
std;
int
main(){
priority_queue<
int
> q;
for
(
int
i= 0; i< 10; ++i ) q.push(
rand
() );
while
( !q.empty() ){
cout << q.top() << endl;
q.pop();
}
getchar
();
return
0;
}
|
#include <iostream>
#include <queue>
using
namespace
std;
int
main(){
priority_queue<
int
, vector<
int
>, greater<
int
> > q;
for
(
int
i= 0; i< 10; ++i ) q.push(
rand
() );
while
( !q.empty() ){
cout << q.top() << endl;
q.pop();
}
getchar
();
return
0;
}
|
#include <iostream>
#include <queue>
using
namespace
std;
struct
Node{
int
x, y;
Node(
int
a= 0,
int
b= 0 ):
x(a), y(b) {}
};
bool
operator<( Node a, Node b ){
if
( a.x== b.x )
return
a.y> b.y;
return
a.x> b.x;
}
int
main(){
priority_queue<Node> q;
for
(
int
i= 0; i< 10; ++i )
q.push( Node(
rand
(),
rand
() ) );
while
( !q.empty() ){
cout << q.top().x <<
' '
<< q.top().y << endl;
q.pop();
}
getchar
();
return
0;
}
|
#include <iostream>
#include <queue>
using
namespace
std;
struct
Node{
int
x, y;
Node(
int
a= 0,
int
b= 0 ):
x(a), y(b) {}
};
struct
cmp{
bool
operator() ( Node a, Node b ){
if
( a.x== b.x )
return
a.y> b.y;
return
a.x> b.x; }
};
int
main(){
priority_queue<Node, vector<Node>, cmp> q;
for
(
int
i= 0; i< 10; ++i )
q.push( Node(
rand
(),
rand
() ) );
while
( !q.empty() ){
cout << q.top().x <<
' '
<< q.top().y << endl;
q.pop();
}
getchar
();
return
0;
}
//以上代码实现的是一个小顶堆
|
转载:http://blog.chinaunix.net/space.php?uid=533684&do=blog&cuid=2615612
ps:如果重载operator > 可直接使用priority_queue<Node,vector<Node>,greater<Node>>