poj1426 Find The Multiple 简单搜索

题目链接：http://poj.org/problem?id=1426

简单的搜索题，一开始想着用bfs，结果TLE了，看有用dfs写A掉了，就用dfs写，过然AC了。

 

bfs超时的代码：

 1 ///2014.4.7
 2 ///poj1426
 3 
 4 #include <iostream>
 5 #include <cstdio>
 6 #include <algorithm>
 7 #include <cstring>
 8 using namespace std;
 9 
10 const int MaxLength = 1000000;
11 unsigned long long queue[MaxLength];
12 int n;
13 
14 unsigned long long bfs( ){
15     memset(queue,0,sizeof(queue) );
16     int head,tail;
17     head = 0;
18     tail = 1;
19     queue[0] = 1;
20 
21     while( true ){
22         queue[tail] = queue[head] * 10;
23         if( queue[tail] % n == 0 )
24             break;
25         tail++;
26 
27         queue[tail] = queue[head] * 10 + 1;
28         if( queue[tail] % n == 0 )
29             break;
30         tail++;
31 
32         head++;
33     }
34     return queue[tail];
35 }
36 
37 int main()
38 {
39     // freopen("in","r",stdin);
40     // freopen("out","w",stdout);
41 
42     while( cin>>n && n ){
43         cout<<bfs( )<<endl;
44     }
45     return 0;
46 }

dfs代码，141MS通过：

 1 ///2014.4.7
 2 ///poj1426
 3 
 4 #include <iostream>
 5 #include <cstdio>
 6 using namespace std;
 7 
 8 bool found;
 9 int n;
10 
11 void dfs(unsigned long long a,int deep){
12     if(found)
13         return;
14     if( a%n == 0 ){
15         found = true;
16         cout<<a<<endl;
17         return;
18     }
19     if( deep>=19 )
20         return;
21     dfs(a*10,deep+1);
22     dfs(a*10+1,deep+1);
23 }
24 
25 int main()
26 {
27     // freopen("in","r",stdin);
28     // freopen("out","w",stdout);
29 
30     while( cin>>n && n ){
31         found = false;
32         dfs(1,0);
33     }
34     return 0;
35 }

 

posted @ 2014-04-07 12:21  basement_boy  阅读(166)  评论(0)  编辑  收藏  举报