优先队列

例子：

#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;}/*运行结果 ：采用默认优先关系:(priority_queue<int>que;)Queue 0:83 72 56 47 36 22 14 10  7  3采用结构体自定义优先级方式一:(priority_queue<int,vector<int>,cmp>que;)Queue 1: 7 10 14 22 36 47 56 72 83 91Queue 2:83 72 56 47 36 22 14 10  7  3采用头文件"functional"内定义优先级:(priority_queue<int,vector<int>,greater<int>/less<int> >que;)Queue 3: 7 10 14 22 36 47 56 72 83 91Queue 4:83 72 56 47 36 22 14 10  7  3采用结构体自定义优先级方式二:(priority_queue<number>que)Queue 5: 7 10 14 22 36 47 56 72 83 91Queue 6:83 72 56 47 36 22 14 10  7  3*/