STL容器之优先队列

1) 优先队列的定义

2) 优先队列的常用操作

 优先级队列支持的操作 q.empty()         如果队列为空，则返回true，否则返回false q.size()            返回队列中元素的个数 q.pop()             删除队首元素，但不返回其值 q.top()             返回具有最高优先级的元素值，但不删除该元素 q.push(item)     在基于优先级的适当位置插入新元素

#include<iostream>
#include<functional>
#include<queue>
#include<vector>
using namespace std;

//定义比较结构
struct cmp1{
bool operator ()(int &a,int &b){
return a>b;//最小值优先
}
};

struct cmp2{
bool operator ()(int &a,int &b){
return a<b;//最大值优先
}
};

//自定义数据结构
struct number1{
int x;
bool operator < (const number1 &a) const {
return x>a.x;//最小值优先
}
};
struct number2{
int x;
bool operator < (const number2 &a) const {
return x<a.x;//最大值优先
}
};
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

priority_queue<int,vector<int>,cmp1>que1;//最小值优先
priority_queue<int,vector<int>,cmp2>que2;//最大值优先

priority_queue<int,vector<int>,greater<int> >que3;//注意“>>”会被认为错误，
priority_queue<int,vector<int>,less<int> >que4;////最大值优先

priority_queue<number1>que5; //最小优先级队列
priority_queue<number2>que6;  //最大优先级队列

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();
}
puts("");
return 0;
}
/*

(priority_queue<int>que;)
Queue 0:
91 83 72 56 47 36 22 14 10  7  3

(priority_queue<int,vector<int>,cmp>que;)
Queue 1:
3  7 10 14 22 36 47 56 72 83 91
Queue 2:
91 83 72 56 47 36 22 14 10  7  3

(priority_queue<int,vector<int>,greater<int>/less<int> >que;)
Queue 3:
3  7 10 14 22 36 47 56 72 83 91
Queue 4:
91 83 72 56 47 36 22 14 10  7  3

(priority_queue<number>que)
Queue 5:
3  7 10 14 22 36 47 56 72 83 91
Queue 6:
91 83 72 56 47 36 22 14 10  7  3
*/

posted on 2012-05-01 22:28  拼装小火车  阅读(...)  评论(...编辑  收藏