zoj 3644(최소 공배수 DP 정보)

#include<stdio.h>
#include<string.h>
#include<math.h>
#include<map>
#define MOD 1000000007
#define Max(a,b) ((a)>(b)?(a):(b))
#define Min(a,b) ((a)<(b)?(a):(b))
#define LL long long
using namespace std;
const int maxn = 20005;
struct edge
{
    int u,v,next;
}e[maxn];
map<LL,int> mp;
int n,m,K,dp[2005][1005];
int head[2005],tot,get[2005];
void add_edge(int u,int v);
int dfs(int now,LL x);
void init();
LL gcd(LL a,LL b){
    return b==0?a:gcd(b,a%b);
}//     
LL lcm(LL a,LL b){
    return a/gcd(a,b)*b;
}//     
int main()
{
    int i;
    while(scanf("%d%d%d",&n,&m,&K) != EOF)
    {
        memset(dp,-1,sizeof(dp));
        memset(head,-1,sizeof(head));
        tot = 0;
        for(i = 0;i < m;i ++)
        {
            int u,v;
            scanf("%d%d",&u,&v);
            add_edge(u,v);
        }
        for(i = 1;i <= n;i ++) scanf("%d",&get[i]);
        init();
        if(mp.find(get[1]) == mp.end())
        {
            printf("0
");
            continue;
        }
        printf("%d
",dfs(1,get[1]));
    }
    return 0;
}
void add_edge(int u,int v)
{
    e[tot].u = u,e[tot].v = v;
    e[tot].next = head[u],head[u] = tot ++;
}
void init()
{
    int i,j,cnt = 0;
    mp.clear();
    for(i = 1;i <= sqrt(K);i ++)
    {
        if(K % i) continue;
        mp[i] = cnt ++;
        mp[K / i] = cnt ++;
    }
}
int dfs(int now,LL x)
{
    if(dp[now][mp[x]] != -1) return dp[now][mp[x]];
    if(now == n)
    {
        if(x == K)  return dp[now][mp[x]] = 1;
        else return dp[now][mp[x]] = 0;
    }
    int i,sum = 0;
    map<LL,int>:: iterator it;
    for(i = head[now];i != -1;i = e[i].next)
    {
        int v = e[i].v;
        LL y = lcm(x,get[v]);
        if(y == x) continue;
        it = mp.find(y);
        if(it == mp.end()) continue;
        sum += dfs(v,y);
        sum %= MOD;
    }
    return dp[now][mp[x]] = sum;
}