HDU5807 Keep In Touch (BestCoder Round #86 D ) 分布式dp

#include <cstdio>
#include <cstring>
#include <cmath>
#include <vector>
#include <algorithm>
using namespace std;
typedef long long LL;
const int N = 50+2;
const int mod = 998244353;
int T,n,m,lim,q,tot,w[N],dp[N][N][N][3],head[N];
struct Edge{
  int v,next;
}edge[N*N/2];
void add(int u,int v){
  edge[tot].v=v;
  edge[tot].next=head[u];
  head[u]=tot++;
}
inline void up(int &x,int y){
  x+=y;if(x>=mod)x-=mod;
}
bool judge(int i,int j){
  return abs(w[i]-w[j])<=lim;
}
int main(){
  scanf("%d",&T);
  while(T--){
    scanf("%d%d%d%d",&n,&m,&lim,&q);
    for(int i=1;i<=n;++i)scanf("%d",&w[i]);
    memset(head,-1,sizeof(head)),tot=0;
    for(int i=0;i<m;++i){
      int u,v;scanf("%d%d",&u,&v);add(v,u);
    }
    memset(dp,0,sizeof(dp));
    for(int i=n;i>0;--i)
     for(int j=n;j>0;--j)
      for(int k=n;k>0;--k){
        if(judge(i,j)&&judge(j,k)&&judge(k,i))
          up(dp[i][j][k][0],1);
        if(dp[i][j][k][0])
          for(int k1=head[i];~k1;k1=edge[k1].next)
            up(dp[edge[k1].v][j][k][1],dp[i][j][k][0]);
        if(dp[i][j][k][1])
          for(int k1=head[j];~k1;k1=edge[k1].next)
            if(!judge(i,edge[k1].v))continue;
            else up(dp[i][edge[k1].v][k][2],dp[i][j][k][1]);
        if(dp[i][j][k][2])
          for(int k1=head[k];~k1;k1=edge[k1].next){
            if(!judge(i,j)||!judge(i,edge[k1].v)||!judge(j,edge[k1].v))
              continue;
            up(dp[i][j][edge[k1].v][0],dp[i][j][k][2]);
          }
      }
     while(q--){
      int x,y,z;
      scanf("%d%d%d",&x,&y,&z);
      printf("%d\n",dp[x][y][z][0]);
     }
  }
  return 0;
}