优先队列 用实验说明问题

优先队列详解

写了一堆代码

#include<cstdio>  #include<queue>  #include<vector>  #include<cstdlib>#include<algorithm>using namespace std;  //定义结构，使用运算符重载,自定义优先级1  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      }  };  //定义结构，使用运算符重载,自定义优先级2  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[]={13,9,55,8,80,25,39,98,5,49,78,0};  number1 num1[]={13,9,55,8,80,25,39,98,5,49,78,0}; number2 num2[]={13,9,55,8,80,25,39,98,5,49,78,0};  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，                                                        //这是右移运算符，所以这里用空格号隔开      priority_queue<int,vector<int>,less<int> >que4;////最大值优先        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("原来的序列:\n");    for(i=0;a[i];i++)     printf("%d ",a[i]);    printf("\n");        printf("采用默认优先关系:\npriority_queue<int>que\n==》:\n");      printf("Queue 0:\n");      while(!que.empty()){          printf("%3d",que.top());          que.pop();      }      puts("");      puts("");         printf("原来的序列:\n");    for(i=0;a[i];i++)     printf("%d ",a[i]);    printf("\n");        printf("采用结构体自定义优先级方式一:\npriority_queue<int,vector<int>,cmp>que\n==》:\n");      printf("Queue 1:\n");      while(!que1.empty()){          printf("%3d",que1.top());          que1.pop();      }      puts("");      printf("原来的序列:\n");    for(i=0;a[i];i++)     printf("%d ",a[i]);    printf("\n");        printf("Queue 2:\n");      while(!que2.empty()){          printf("%3d",que2.top());          que2.pop();      }      puts("");      puts("");          printf("原来的序列:\n");    for(i=0;a[i];i++)     printf("%d ",a[i]);    printf("\n");        printf("内定义优先级:\npriority_queue<int,vector<int>,greater<int>/less<int> >que\n==》:\n");  printf("Queue 3:\n");      while(!que3.empty()){          printf("%3d",que3.top());          que3.pop();      }      puts(""); printf("原来的序列:\n");    for(i=0;a[i];i++)     printf("%d ",a[i]);    printf("\n");         printf("Queue 4:\n");      while(!que4.empty()){          printf("%3d",que4.top());          que4.pop();      }      puts("");      puts(""); printf("原来的序列:\n");    for(i=0;a[i];i++)     printf("%d ",a[i]);    printf("\n");     printf("采用结构体自定义优先级方式二:\npriority_queue<number>que\n==》:\n");      printf("Queue 5:\n");      while(!que5.empty()){          printf("%3d",que5.top());          que5.pop();      }      puts("");          printf("原来的序列:\n");    for(i=0;a[i];i++)     printf("%d ",a[i]);    printf("\n");        printf("Queue 6:\n");      while(!que6.empty()){          printf("%3d",que6.top());          que6.pop();      }      puts("");      return 0;  }  

结果：