算法：优先级队列

优先级队列:
 1 #include <stdio.h>
 2 
 3 int A[100];
 4 int heapsize;
 5 
 6 void swap(int i, int j) {
 7     int temp = A[i];
 8     A[i] = A[j];
 9     A[j] = temp;
10 }
11 
12 void huifu(int i){
13     int maxheap = i;
14     int l = 2*i;
15     int r = 2*i + 1;
16     if(l <= heapsize && A[l] > A[maxheap])
17         maxheap = l;
18     if(r <= heapsize && A[r] > A[maxheap])
19         maxheap = r;
20     if(i != maxheap){
21         swap(maxheap, i);
22         huifu(maxheap);
23     }
24 }    
25 
26 
27 void sort(){
28     while(heapsize>1) {
29         swap(heapsize, 1);
30         --heapsize;
31         huifu(1);
32     }
33 }
34 
35 void insert(int x){
36     int i;
37     A[++heapsize] = x;
38     i = heapsize;
39     while(i > 1 && A[i] > A[i/2]) {
40         swap(i, i/2);
41         i >>= 1;
42     }
43     /*
44     while(A[heapsize] > i && i>=0){
45         i/=2;
46         swap(A[heapsize], A[i]);
47     }*/
48 }
49 
50 int  max(){
51     return A[1];
52 }
53 
54 int extract_max(){
55     int tmp = A[1];
56     A[1] = A[heapsize--];
57     huifu(1);
58     return tmp;
59 }
60 
61 void build(){
62     int i;
63     for(i=heapsize/2; i>0 ;--i){
64         huifu(i);
65     }
66 }
67 
68 int main(int argc, char const *argv[])
69 {
70     int n, i;
71     scanf("%d", &n);
72     heapsize = n;
73     for(i=1;i<=n;++i){
74         scanf("%d", &A[i]);
75     }
76     build();
77     sort();
78     // insert(24);
79     // insert(20);
80     // insert(100);
81     for(i = 1; i <= n; i++)
82         printf("%d
", A[i]);
83     return 0;
84 }