ZOJ 3644 Kitty's Game

主要难点在于寻找到一个合适的拓扑结构，剩下的就是dp或者记忆化搜索

#include<iostream>#include<vector>#include<algorithm>#include<cstdio>#include<queue>#include<stack>#include<string>#include<map>#include<set>#include<cmath>#include<cassert>#include<cstring>#include<iomanip>using namespace std;#ifdef _WIN32#define i64 __int64#define out64 "%I64d\n"#define in64 "%I64d"#else#define i64 long long#define out64 "%lld\n"#define in64 "%lld"#endif/************ for topcoder by zz1215 *******************/#define FOR(i,a,b)      for( int i = (a) ; i <= (b) ; i ++)#define FFF(i,a)        for( int i = 0 ; i < (a) ; i ++)#define FFD(i,a,b)      for( int i = (a) ; i >= (b) ; i --)#define S64(a)          scanf(in64,&a)#define SS(a)           scanf("%d",&a)#define LL(a)           ((a)<<1)#define RR(a)           (((a)<<1)+1)#define pb              push_back#define CL(Q)           while(!Q.empty())Q.pop()#define MM(name,what)   memset(name,what,sizeof(name))#define MC(a,b)memcpy(a,b,sizeof(b))#define MAX(a,b)        ((a)>(b)?(a):(b))#define MIN(a,b)        ((a)<(b)?(a):(b))#define read            freopen("in.txt","r",stdin)#define write           freopen("out.txt","w",stdout)const int inf = 0x3f3f3f3f;const i64 inf64 = 0x3f3f3f3f3f3f3f3fLL;const double oo = 10e9;const double eps = 10e-9;const double pi = acos(-1.0);const int maxn = 2011;const int maxf = 1000;const int mod = 1000000007;int dp[maxn][maxf];vector<int>fac;map<int,int>mp;int n,m,k;int f[maxn];int cnt;vector<int>g[maxn];int gcd(int _a, int _b){    if (!_a || !_b)    {        return max(_a, _b);    }    int _t;    while ((_t = _a % _b))    {        _a = _b;        _b = _t;    }    return _b;}void dps(){int now,to;int y;i64 temp;for(int x=0;x<cnt-1;x++){for(now=1;now<=n;now++){if(dp[now][x]){for(int i=0;i<g[now].size();i++){to = g[now][i];if(fac[x]%f[to]){temp = fac[x];temp*= f[to];temp/= gcd(fac[x],f[to]);y = mp[temp];if(y){dp[to][y]+=dp[now][x];dp[to][y]%=mod;}}}}}}return ;}void start(){int temp = sqrt(k);fac.clear();for(int i=1;i<=temp;i++){if(k%i==0){fac.pb(i);fac.pb(k/i);}}if(temp*temp==k){fac.pop_back();}sort(fac.begin(),fac.end());cnt = fac.size();mp.clear();for(int i=0;i<cnt;i++){mp[fac[i]]=i;}for(int i=1;i<=n;i++){for(int j=0;j<=cnt;j++){dp[i][j]=0;}}dp[1][mp[f[1]]]=1;dps();return ;}int main(){int now,to;while(cin>>n>>m>>k){for(int i=0;i<=n;i++){g[i].clear();}for(int i=1;i<=m;i++){SS(now);SS(to);g[now].pb(to);}for(int i=1;i<=n;i++){SS(f[i]);}start();cout<<dp[n][cnt-1]<<endl;}return 0;}