a min heap for priority queue code example
Example 1: priority queue min heap
#include <bits/stdc++.h>
using namespace std;
class Point
{
int x;
int y;
public:
Point(int _x, int _y)
{
x = _x;
y = _y;
}
int getX() const { return x; }
int getY() const { return y; }
};
class myComparator
{
public:
int operator() (const Point& p1, const Point& p2)
{
return p1.getX() > p2.getX();
}
};
int main ()
{
priority_queue <Point, vector<Point>, myComparator > pq;
pq.push(Point(10, 2));
pq.push(Point(2, 1));
pq.push(Point(1, 5));
while (pq.empty() == false)
{
Point p = pq.top();
cout << "(" << p.getX() << ", " << p.getY() << ")";
cout << endl;
pq.pop();
}
return 0;
}
Example 2: priority queue max heap in java
PriorityQueue<Integer> queue = new PriorityQueue<>(10, Collections.reverseOrder());
PriorityQueue<Integer> pq =new PriorityQueue<>((x, y) -> Integer.compare(y, x));
PriorityQueue<Integer> pq = new PriorityQueue<Integer>(defaultSize, new Comparator<Integer>() {
public int compare(Integer lhs, Integer rhs) {
if (lhs < rhs) return +1;
if (lhs.equals(rhs)) return 0;
return -1;
}
});