pku1056 IMMEDIATE DECODABILITY

http://poj.org/problem?id=1056
Trie
有一些字符串，判断是否：这些字符串之间都不是彼此的前缀
 1 #include <stdio.h>
 2 #include <string.h>
 3 
 4 const int CHARSET = 2, BASE = '1', MAX_NODE = 1001; 
 5 
 6 int tot, root, child[MAX_NODE][CHARSET];
 7 bool flag[MAX_NODE];
 8 
 9 void init()
10 {
11     memset(child, 0, sizeof(child));
12     flag[1] = false;
13     root = tot = 1;
14 }
15 
16 int insert(const char *str)
17 {
18     int i, cur, j, flag1 = 0, flag2 = 0;
19     cur = root;
20     for(i=0; str[i]; i++)
21     {
22         if(child[cur][str[i]-BASE] == 0)
23         {
24             if(flag[cur])
25             {
26                 flag2 = 1;
27             }
28             flag1 = 1;
29             tot = tot + 1;
30             child[cur][str[i]-BASE] = tot;
31             memset(child[tot], 0, sizeof(child[tot]));
32             flag[tot] = false;
33         }
34         cur = child[cur][str[i]-BASE];
35     }
36     flag[cur] = true;
37     if(flag1 == 0 || flag2 == 1)
38     {
39         return 1;//重复 
40     }
41     return 0;
42 }
43 
44 
45 
46 int main()
47 {
48     char s[12] = "\0";
49     int cases = 1, temp, flag = 0;
50     init();
51     while(~scanf("%s", s))
52     {
53         if(strcmp(s, "9") == 0)
54         {
55             if(flag)
56             {
57                 printf("Set %d is not immediately decodable\n", cases);
58             }
59             else
60             {
61                 printf("Set %d is immediately decodable\n", cases);
62             }
63             cases ++;
64             flag = 0;
65             init();
66         }
67         else
68         {
69             temp = insert(s);
70             //printf("%d\n", temp);
71             flag |= temp;
72         }
73         memset(s, 0, sizeof(s));
74     }
75     return 0;
76 }