[ZOJ 1003] Crashing Balloon (dfs搜索)

题目链接：http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=3

题目大意：给你a，b两个数，问当b由约数1到100组成时，a能否由其它约数也在1到100的组成

就是dfs先枚举b的乘积组合，再看a有没有组合能够乘出来。。

代码：

 #include <cstdio>
 #include <cstdlib>
 #include <string>
 #include <iostream>
 #include <cstring>
 #include <algorithm>
 #include <cctype>
 #include <vector>
 #include <map>
 #include <set>
 #include <iterator>
 #include <functional>
 #include <cmath>
 #include <numeric>
 using namespace std;
 typedef long long LL;
 typedef pair<int,int> PII;
 typedef vector<int> VI;
 #define PB push_back
 #define MP make_pair
 #define SZ size()
 #define CL clear()
 #define AA first
 #define BB second
 #define EPS 1e-8
 #define ZERO(x) memset((x),0,sizeof(x))
 const int INF = ~0U>>;
 const double PI = acos(-1.0);

 int a,b;
 VI aa,bb;
 bool vis[];
 bool ok;
 bool cansmall;

 bool dfsa(int cur,int now=){
     bool res = false;
     if(now==a){
         return true;
     }
     if( now>a ) return false;
     if( cur<aa.SZ ) res = res || dfsa(cur+,now);
     if( cur<aa.SZ&&!vis[aa[cur]] ){
         vis[aa[cur]] = true;
         res = res||dfsa(cur+,now*aa[cur]);
         vis[aa[cur]] = false;
     }
     return res;
 }

 void dfsb(int cur,int now=){
 //    printf("now=%d\n",now);
     if( ok ) return;
     if(now==b){
         cansmall = true;
         bool flag = dfsa();
         if( flag ){
             ok = true;
         }
         return;
     }
     if( now>a ) return;
     if( cur<bb.SZ ) dfsb(cur+,now);
     if( cur<bb.SZ&&!vis[bb[cur]] ){
         vis[bb[cur]] = ;
         dfsb(cur+,now*bb[cur]);
         vis[bb[cur]] = ;
     }
 }

 int main(){
     while(scanf("%d%d",&a,&b)!=EOF){
         if(a<b) swap(a,b);
         aa.clear();
         bb.clear();
         for(int i=;i<=;i++){
             if( a%i== ) aa.PB(i);
             if( b%i== ) bb.PB(i);
         }

         ZERO(vis);

         ok = cansmall = false;

         dfsb();

         if( ok||!cansmall ) {
             printf("%d\n",a);
         } else {
             printf("%d\n",b);
         }
     }
     return ;
 }