萌新求助CE

P4221 [WC2018] 州区划分

```cpp #include<bits/stdc++.h> #define I inline #define max(a,b) ((a)>(b)?(a):(b)) #define min(a,b) ((a)<(b)?(a):(b)) #define abs(x) ((x)>0?(x):-(x)) #define re register #define RI re int #define ll long long #define db double #define lb long db #define N 21 #define K (1<<N) #define mod 998244353 #define Mod 998244352 #define eps (1e-4) #define U unsigned int #define it iterator #define Gc() getchar() #define Me(x,y) memset(x,y,sizeof(x)) #define d(x,y) (n*(x-1)+(y)) using namespace std; int n,m,k,p,x[N*N+5],y[N*N+5],In[N+5],W[K+5],H[K+5],cnt,un,wn,Fl,lg[K+5],fa[K+5],F1[N+1][K+5],F2[N+1][K+5];ll G[K+5],Inv[K+5]; I ll mpow(ll x,int y=mod-2){ll Ans=1;while(y) y&1&&(Ans=Ans*x%mod),y>>=1,x=x*x%mod;return Ans;} I void OR(int *A,int n,int Fl){ RI i,j,h;for(i=2;i<=n;i<<=1){ for(j=0;j<n;j+=i) for(h=j;h<j+i/2;h++) A[h+i/2]=(1ll*A[h+i/2]+mod+A[h]*Fl)%mod; } }I int Getfa(int x){return x==fa[x]?x:fa[x]=Getfa(fa[x]);} I void merge(int x,int y){un=Getfa(x);wn=Getfa(y);un^wn&&(fa[un]=wn,cnt--);} int main(){ freopen("1.in","r",stdin); RI i,j,h;scanf("%d%d%d",&n,&m,&p);k=1<<n;for(i=1;i<=m;i++) scanf("%d%d",&x[i],&y[i]);for(i=1;i<=n;i++)scanf("%d",&W[i]);for(i=1;i<k;i++) lg[i]=lg[i/2]+1; for(i=1;i<k;i++)H[i]=H[i>>1]+(i&1),G[i]=(G[i^(i&-i)]+W[lg[i&-i]])%mod; for(i=0;i<k;i++){ Me(In,0);for(j=1;j<=n;j++) fa[j]=j;cnt=H[i];G[i]=mpow(G[i],p);Inv[i]=G[i]?mpow(G[i]):1;for(j=1;j<=m;j++) i>>(x[j]-1)&1&&i>>(y[j]-1)&1&&(merge(x[j],y[j]),In[x[j]]^=1,In[y[j]]^=1); for(Fl=j=1;j<=n;j++) i>>(j-1)&1&&(Fl&=In[j]^1);F1[H[i]][i]=G[i]*(Fl^1||cnt^1); }F2[0][0]=1;OR(F2[0],k,1);for(i=1;i<=n;i++){ OR(F1[i],k,1);for(j=1;j<=i;j++) for(h=0;h<k;h++) F2[i][h]=(F2[i][h]+1ll*F1[j][h]*F2[i-j][h])%mod;OR(F2[i],k,-1); for(j=0;j<k;j++) F2[i][j]=1ll*F2[i][j]*Inv[j]%mod;OR(F2[i],k,1); }OR(F2[n],k,-1);printf("%d\n",F2[n][k-1]); } ```
by 275307894a @ 2021-09-18 20:19:46


评测机波动
by 天有不测风云 @ 2021-09-18 20:19:54


楼上正解
by wssbi @ 2021-09-18 20:20:50


@[275307894a](/user/181766) 你谷日爆
by j1ANGFeng @ 2021-09-18 20:22:50


|