c-PriorityQuque
/*@file test.c*/
/*compiled ok with mingGW/gcc chinayaosir*/
/*优先队列测试程序*/
#include <stdio.h>
#include "pqueue.h"
int main()
{
// Example use of priority queue
pqueue queue;
node n1, n2, n3,n4,n5,t;
n1.data = 12; n1.priority = 3;/*level 3*/
n2.data = 25; n2.priority = 1;/*level 1*/
n3.data = 66; n3.priority = 4;/*level 4*/
n4.data = 22; n4.priority = 2;/*level 2*/
n5.data = 99; n5.priority = 0;/*level 0*/
/*初始化队列*/
init_queue(&queue);
/*入队5个结点*/
printf("1.结点5个依次入队/n");
enqueue(&queue, &n1);
printf("(数据=%d,级别=%d )/n",n1.data,n1.priority);
enqueue(&queue, &n2);
printf("(数据=%d,级别=%d )/n",n2.data,n2.priority);
enqueue(&queue, &n3);
printf("(数据=%d,级别=%d )/n",n3.data,n3.priority);
enqueue(&queue, &n4);
printf("(数据=%d,级别=%d )/n",n4.data,n4.priority);
enqueue(&queue, &n5);
printf("(数据=%d,级别=%d )/n",n5.data,n5.priority);
printf("2.打印/n");
print_queue(&queue);
printf("3.出队()/n");
t=dequeue(&queue);/*元素出队*/
print_queue(&queue);
printf("4.出队()/n");
t=dequeue(&queue);/*元素出队*/
print_queue(&queue);
printf("5.出队()/n");
t=dequeue(&queue);/*元素出队*/
print_queue(&queue);
return 0;
}
/*
运行结果
1.结点5个依次入队
(数据=12,级别=3 )
(数据=25,级别=1 )
(数据=66,级别=4 )
(数据=22,级别=2 )
(数据=99,级别=0 )
2.打印
[ 99 25 66 12 22 ]
3.出队()
[ 25 22 66 12 ]
4.出队()
[ 22 12 66 ]
5.出队()
[ 12 66 ]
*/
/****************************************************************/
/**@file pqueue.h
*功能:基于数组的二项堆构建一个优先队列.
*compiled ok with mingGW/vc++ with chinayaosir
*/
#include <stdlib.h>
/*1.堆操作宏定义 */
#define PARENT(i) ((i-1)/2)
#define LEFT(i) ((2*i+1))
#define RIGHT(i) (2*(i+1))
#define priority(i) (i.priority)
#define TRUE 1
#define FALSE 0
#define NULL 0
#define PQUEUESIZE 1000
/*2.node struct*/
typedef int datatype;
typedef struct {
int x; /* x 坐标 */
int y; /* y 坐标 */
int priority; /* node优先级别 */
datatype data; /* node的数据*/
struct node * parent; /* link to parent node */
}node;
/*3.priority-quque struct*/
typedef struct {
node q[PQUEUESIZE+1]; /* 结点数组 */
int count; /* 元素个数 */
} pqueue;
/*priority ADT LIST*/
/*0.1.empty()*/
int empty(pqueue *q){
if (q->count == 0)
return (TRUE);
else
return (FALSE);
}
/*0.2.contains()*/
int contains(pqueue *q, node *n){
int i;
for(i=0; i<q->count; i++){
if(q->q[i].data == n->data)
return (TRUE);
}
return (FALSE);
}
/*0.3.print_queue()*/
print_queue(pqueue *q){
int i;
printf("[ ");
for(i=0; i<q->count; i++) printf("%d ",q->q[i].data);
printf("]/n");
}
/*1.init_queue*/
void init_queue(pqueue *q){
q->count = 0;
}
/*2.enqueue(pqueue *, node * )入队*/
/*入队之前，node的节点一定要填好数据内容和优先级别*/
void enqueue(pqueue *q, node * x){
int parent, leaf;
node value, temp;
/*2.1检查是否为空?*/
if (q->count >= PQUEUESIZE){
printf("Warning: pqueue overflow enpqueue x=%dn",x);
return;
}
/*2.2添加结点node*/
q->count++;
leaf = q->count - 1;
q->q[leaf] = *x;
/*2.3队列中结点的数据按priority从小到大进行提升*/
parent = PARENT(leaf);
value = q->q[leaf];
while(leaf > 0 && (priority(q->q[leaf]) < priority(q->q[parent]))){
temp = q->q[leaf];
q->q[leaf] = q->q[parent];
q->q[parent] = temp;
leaf = parent;
parent = PARENT(leaf);
}
q->q[leaf] = value;
}
/*3.dequeue(pqueue *)出队*/
/*找出队列中priority最小的结点node出队*/
node dequeue(pqueue *q)
{
int heapsize, root, childpos;
node minVal, temp;
node value;
minVal = q->q[0];
q->q[0] = q->q[q->count-1]; // take last element and put on root of tree
q->count--; // adjust size
root = 0;
if(q->count > 1)
{
// percolate down
heapsize = q->count;
value = q->q[root]; // get root
while(root < heapsize)
{
childpos = LEFT(root);
if(childpos < heapsize)
{
if((RIGHT(root) < heapsize) &&
(priority(q->q[childpos+1]) <
priority(q->q[childpos])))
{
childpos++;
}
if(priority(q->q[childpos]) < priority(q->q[root]))
{
temp = q->q[root];
q->q[root] = q->q[childpos];
q->q[childpos] = temp;
root = childpos;
}
else
{
q->q[root] = value;
break;
}
}
else
{
q->q[root] = value;
break;
}
}
}
return minVal;/*返回级别最高的结点*/
}