= 3345 binary tree data structure of six experiments: Huffman encoding

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include <string.h>
 4 char s[2000];
 5 int num[2000],queue[2000];
 6 void so(int s[],int l,int r)
 7 {
 8     if(l>=r)return;
 9     int i=l,j=r;
10     int temp=s[l];
11     while(i<j)
12     {
13         while(i<j&&s[j]>=temp)j--;
14         s[i]=s[j];
15         while(i<j&&s[i]<=temp)i++;
16         s[j]=s[i];
17     }
18     s[i]=temp;
19     so(s,l,i-1);
20     so(s,i+1,r);
21 }
22 int main()
23 {
24     while(~scanf("%s",s))
25     {
26         int top = 0,i;
27         int len = strlen(s);
28         memset(num,0,sizeof(num));
29         memset(queue,0,sizeof(queue));
30         for(i=0; i<len; i++)
31         {
32             num[s[i]]++;
33         }
34         for(i=0; i<500; i++)
35         {
36             if(num[i]!=0)
37             {
38                 queue[top++]=num[i];
39             }
40         }
41         so(queue,0,top-1);
42         int be=0;
43         int sum=0;
44 //----------------------------------------------------------------------
45         while(be!=top)
46         {
47             int x = queue[be++];
48             if(be!=top)
49             {
50                 int y = queue[be++];
51                 queue[top++] = x+y;
52                 sum = sum+x+y;
53                 so(queue,be,top-1);
54             }
55         }
56         printf("%d %d %.1lf\n",8*len,sum,8.0*len/sum);
57     }
58     return 0;
59 }