priority_queue使用方法

priority_queue: 默认
9 6 5 3 2

由小到大：
priority_queue<int, vector<int>, greater<int> >
2 3 5 6 9;

由大到小：
struct node
{
friend bool operator< (node n1, node n2)
{
return n1.priority < n2.priority;
}
int priority;
int value;
};

9 6 5 3 2

priority_queue<int> que;
que.push();
que.top();

que.pop();

[cpp] view plain copy

print?

#include<iostream>

#include<functional>

#include<queue>

#include<vector>

using namespace std;

struct cmp1

{

bool operator () (int &a, int &b)

{

return a > b ; // 从小到大排序，值 小的 优先级别高

}

};

struct cmp2

{

bool operator () (int &a, int &b)

{

return a < b; // 从大到小

}

};

struct number1

{

int x;

bool operator < (const number1 &a)const

{

return x > a.x; // 从小到大 ，x 小的 优先级别高

}

};

struct number2

{

int x;

bool operator < (const number2 &a)const

{

return x < a.x; // 从大到小 ，x 大的优先级别高

}

};

int a[] = {14,10,56,7,83,22,36,91,3,47,72,0};

number1 num1[] ={14,10,56,7,83,22,36,91,3,47,72,0};

number2 num2[] ={14,10,56,7,83,22,36,91,3,47,72,0};

int main()

{

priority_queue<int>que; // 采用默认优先级构造队列 从大到小。

priority_queue<int, vector<int>, cmp1 >que1;

priority_queue<int, vector<int>, cmp2 >que2;

priority_queue<int, vector<int>, greater<int> > que3; //functional 头文件自带的

priority_queue<int, vector<int>, less<int> > que4; //functional 头文件自带的

priority_queue<number1> que5;

priority_queue<number2> que6;

int i;

for(i=0;a[i];i++)

{

que.push(a[i]);

que1.push(a[i]);

que2.push(a[i]);

que3.push(a[i]);

que4.push(a[i]);

}

for(i=0;num1[i].x;i++)

que5.push(num1[i]);

for(i=0;num2[i].x;i++)

que6.push(num2[i]);

printf("采用默认优先关系:\n(priority_queue<int>que;)\n");

printf("Queue 0:\n");

while(!que.empty())

{

printf("%3d",que.top());

que.pop();

}

puts("");

puts("");

printf("采用结构体自定义优先级方式一:\n(priority_queue<int,vector<int>,cmp>que;)\n");

printf("Queue 1:\n");

while(!que1.empty())

{

printf("%3d",que1.top());

que1.pop();

}

puts("");

printf("Queue 2:\n");

while(!que2.empty())

{

printf("%3d",que2.top());

que2.pop();

}

puts("");

puts("");

printf("采用头文件\"functional\"内定义优先级：\n(priority_queue<int, vector<int>,greater<int>/less<int> >que;)\n");

printf("Queue 3:\n");

while(!que3.empty())

{

printf("%3d",que3.top());

que3.pop();

}

puts("");

printf("Queue 4 :\n");

while(!que4.empty())

{

printf("%3d",que4.top());

que4.pop();

}

puts("");

puts("");

printf("采用结构体自定义优先级方式二:\n(priority_queue<number>que)\n");

printf("Queue 5:\n");

while(!que5.empty())

{

printf("%3d",que5.top());

que5.pop();

}

puts("");

printf("Queue 6:\n");

while(!que6.empty())

{

printf("%3d",que6.top());

que6.pop();

}

system("pause");

return 0;

}