LuoguP2542 [AHOI2005] 航线规划

#include<bits/stdc++.h>
#define Tp template<typename Ty>
#define Ts template<typename Ty,typename... Ar>
#define W while
#define I inline
#define RI register int
#define LL long long
#define Cn const
#define CI Cn int&
#define gc getchar
#define D isdigit(c=gc())
#define pc(c) putchar((c))
#define min(x,y) ((x)<(y)?(x):(y))
#define max(x,y) ((x)>(y)?(x):(y))
using namespace std;
namespace Debug{
    Tp I void _debug(Cn char* f,Ty t){cerr<<f<<'='<<t<<endl;}
    Ts I void _debug(Cn char* f,Ty x,Ar... y){W(*f!=',') cerr<<*f++;cerr<<'='<<x<<",";_debug(f+1,y...);}
    Tp ostream& operator<<(ostream& os,Cn vector<Ty>& V){os<<"[";for(Cn auto& vv:V) os<<vv<<",";os<<"]";return os;}
    #define gdb(...) _debug(#__VA_ARGS__,__VA_ARGS__)
}using namespace Debug;
namespace FastIO{
    Tp I void read(Ty& x){char c;int f=1;x=0;W(!D) f=c^'-'?1:-1;W(x=(x<<3)+(x<<1)+(c&15),D);x*=f;}
    Ts I void read(Ty& x,Ar&... y){read(x),read(y...);}
    Tp I void write(Ty x){x<0&&(pc('-'),x=-x,0),x<10?(pc(x+'0'),0):(write(x/10),pc(x%10+'0'),0);}
    Tp I void writeln(Cn Ty& x){write(x),pc('\n');}
}using namespace FastIO;
Cn int N=3e4+10,M=1e5+10,Qt=4e4+10;
int n,m,q,fir[N],nxt[M<<1],son[M<<1],tot,mx[N],sz[N],F[N],top[N],id[N],dep[N],Ans[N],cnt;
I void Add(CI x,CI y){nxt[++tot]=fir[x],fir[x]=tot,son[tot]=y;}
#define to son[i]
struct Que{int op,x,y;}Q[Qt];
#define P pair<int,int>
#define MP make_pair
map<P,int> mp;
I void Dfs(CI x,CI fa){
    RI i;for(sz[x]=1,dep[x]=dep[F[x]=fa]+1,i=fir[x];i;i=nxt[i]) !mp[MP(x,to)]&&to^fa&&!sz[to]&&(Dfs(to,x),sz[x]+=sz[to],sz[mx[x]]<sz[to]&&(mx[x]=to));
}
I void Dfs2(CI x,CI Top){
    if(top[x]=Top,id[x]=++cnt,mx[x]) Dfs2(mx[x],Top);RI i;for(i=fir[x];i;i=nxt[i]) !mp[MP(x,to)]&&to^mx[x]&&F[to]==x&&to^F[x]&&(Dfs2(to,to),0);
}
class Tree{
    private:
        class SegmentTree{
            private:
                struct node{int S,T;}T[N<<2];
                #define mid (l+r>>1)
                #define PT CI x=1,CI l=1,CI r=n
                #define LT x<<1,l,mid
                #define RT x<<11,mid+1,r
                #define PD(x) (T[x].T&&(T[x<<1].S=T[x<<11].S=0,T[x<<1].T=T[x<<11].T=1,T[x].T=0))
                #define PU(x) (T[x].S=T[x<<1].S+T[x<<11].S)
            public:
                I void B(PT){
                    if(l==r) return void(T[x]=(node){1,0});
                    B(LT),B(RT),PU(x);
                }
                I void U(CI L,CI R,PT){
                    if(L<=l&&r<=R) return T[x].T=1,T[x].S=0,void();
                    PD(x),L<=mid&&(U(L,R,LT),0),R>mid&&(U(L,R,RT),0),PU(x);
                }
                I int Q(CI L,CI R,PT){
                    if(L<=l&&r<=R) return T[x].S;
                    RI S=0;return PD(x),L<=mid&&(S+=Q(L,R,LT)),R>mid&&(S+=Q(L,R,RT)),S;
                }
        }S;
    public:
        I void B(){S.B();}
        I void U(RI x,RI y){
            W(top[x]^top[y]) dep[top[x]]<dep[top[y]]&&(swap(x,y),0),S.U(id[top[x]],id[x]),x=F[top[x]];
            dep[x]<dep[y]&&(swap(x,y),0),x^y&&(S.U(id[y]+1,id[x]),0);
        }
        I int Q(RI x,RI y){
            RI X=0;W(top[x]^top[y]) dep[top[x]]<dep[top[y]]&&(swap(x,y),0),X+=S.Q(id[top[x]],id[x]),x=F[top[x]];
            return dep[x]<dep[y]&&(swap(x,y),0),x^y&&(X+=S.Q(id[y]+1,id[x])),X;
        }
}T;
I void B(CI x){
    RI i;for(i=fir[x];i;i=nxt[i]) !mp[MP(x,to)]&&(F[to]==x&&(B(to),0),to^F[x]&&dep[to]<dep[x]&&(T.U(x,to),0));
}
int main(){
    RI i,op,x,y;for(read(n,m),i=1;i<=m;i++) read(x,y),Add(x,y),Add(y,x);
    W(read(op),~op) read(x,y),Q[++q].op=op,Q[q].x=x,Q[q].y=y,!op&&(mp[MP(Q[q].y,Q[q].x)]=mp[MP(Q[q].x,Q[q].y)]=1);
    for(Dfs(1,0),Dfs2(1,1),T.B(),B(1),i=q;i;i--) Q[i].op?void(Ans[i]=T.Q(Q[i].x,Q[i].y)):T.U(Q[i].x,Q[i].y);
    for(i=1;i<=q;i++) Q[i].op&&(writeln(Ans[i]),0);return 0;
}