题意
Solution
压位+前缀和
1 #include <cstdio> 2 #include <iostream> 3 #include <cmath> 4 #include <algorithm> 5 #define ll int 6 using namespace std; 7 const ll mod=100000007; 8 inline void read(ll &k) 9 { 10 ll f=1;char c=getchar();k=0; 11 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 12 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 13 k*=f; 14 } 15 const int maxn=1000010; 16 ll n,q,k,aa,bb,cc; 17 ll last[maxn],next[maxn],tot,c[maxn],to[maxn],sum[maxn];long long cost[233]; 18 bool v[maxn]; 19 void dfs(ll now,ll fa) 20 { 21 v[now]=1;ll cur=last[now]; 22 while (cur) 23 { 24 if (!v[to[cur]]) 25 { 26 sum[to[cur]]=sum[now]^(1<<(c[cur]-1)); 27 dfs(to[cur],now); 28 } 29 cur=next[cur]; 30 } 31 } 32 int main() 33 { 34 freopen("mahou.in","r",stdin); 35 freopen("mahou.out","w",stdout); 36 read(n);read(q);read(k); 37 // printf("..............qaq%lld%lld%lld ",n,q,k); 38 for (int i=1;i<n;i++) 39 { 40 read(aa);read(bb);read(cc); 41 to[++tot]=bb; 42 next[tot]=last[aa]; 43 last[aa]=tot; 44 c[tot]=cc; 45 to[++tot]=aa; 46 next[tot]=last[bb]; 47 last[bb]=tot; 48 c[tot]=cc; 49 } 50 dfs(1,0); 51 for (int i=1;i<=k;i++)scanf("%lld",&cost[i]); 52 ll pp,qq; 53 for (int i=1;i<=q;i++) 54 { 55 long long ans=1; 56 read(pp);read(qq); 57 ll cur=sum[pp]^sum[qq]; 58 for (int j=1;j<=k;j++) 59 if (cur&(1<<(j-1)))ans=(long long)((long long)ans*cost[j])%mod; 60 printf("%lld ",ans%mod); 61 }/* 62 for (int i=1;i<=n;i++){printf("%d ",i); 63 for (int j=1;j<=k;j++) 64 printf("%lld ",sum[i][j]); 65 printf(" "); 66 }*/ 67 }