TLE: poj 1011 Sticks

Ozy的方法（dfs）：

 1 # include <stdio.h>
 2 # include <string.h>
 3 
 4 int f[51];
 5 int ok;
 6 int length;
 7 
 8 void dfs(int cnt, int len, int cur)
 9 {
10     int j;
11     
12     if (cnt == 0) {ok = 1; return;}
13     
14     --f[cur];
15     
16     len -= cur;
17     if (len != 0)
18     {
19         j = len<cur ? len:cur;
20         for (; j > 0; --j)
21             if (f[j]) dfs(cnt, len, j);
22     }
23     else 
24     {
25         for (j = 50; !f[j] ; ) --j;
26         dfs(cnt-1, length, j);
27     }
28     
29     ++f[cur];
30 }
31 
32 int main()
33 {
34     int i, n, x, max, sum;
35     
36     while (1)
37     {
38         scanf("%d", &n);
39         if (n == 0) break;
40         
41         ok = 0;
42         sum = max = 0;
43         memset(f, 0, sizeof(f));
44         
45         for (i = 1; i <= n; ++i)
46         {
47             scanf("%d", &x);
48             ++f[x];
49             sum += x;
50             if (x > max) max = x;
51         }
52         
53         for (length = max; !ok ; ++length)
54             if (sum%length == 0) dfs(sum/length, length, max);
55 
56            printf("%d\n", length-1);
57     }
58     
59     return 0;
60 }