BZOJ 2588 Spoj 10628 Count on a tree

说来惭愧，这么多天才a了一道题，怎比得上当时myc在二十分钟内就切了此题

正解就是dfs一遍，搞出主席树，然后每次lca完在主席树上询问,非常裸

//By Richard#include <cstdio>#include <algorithm>#include <iostream>#include <cstring>#include <map>#include <cstdlib>#include <cmath>#include <ctime>#define rep(x,y,z) for (int x=(y);(x)<=(z);(x)++)#define per(x,y,z) for (int x=(y);(x)>=(z);(x)--)#define log2(x) (int)(31-__builtin_clz(x))#define mod (int)(1e9+7)#define inf 0x3f3f3f3f#define cls(x) memset(x,0,sizeof(x))#ifdef DEBUG#define debugdo(X) X#define debugndo(X)#define debugout(X) cout<<(#X)<<"="<<(X)<<endl#else#define debugdo(X)#define debugndo(X) X#define debugout(X)#endif // debug#ifdef ONLINE_JUDGE#define debugdo(X)#define debugndo(X)#define debugout(X)#endif#define putarray(x,n) rep(iiii,1,n) printf("%d ",x[iiii])#define mp make_pairusing namespace std;typedef pair<int,int> pairs;typedef long long LL;/////////////////////read4.0////////////////////////////////////template <typename T>inline void read(T &x){char ch;x=0;bool flag=false;ch=getchar();while (ch>'9'||ch<'0') {if (ch=='-') flag=true;ch=getchar();}while ((ch<='9'&&ch>='0')){x=x*10+ch-'0';ch=getchar();}if (flag) x*=-1;}template <typename T>inline void read(T &x,T &y){read(x);read(y);}template <typename T>inline void read(T &x,T &y,T &z){read(x);read(y);read(z);}/////////////////////graph///////////////////////////////#ifdef graphvconst int maxn=,maxm=;struct GRAPH{int next[maxm],first[maxn],to[maxm],value[maxm],cnt;void addedge(int x,int y,int z){next[++cnt]=first[x];first[x]=cnt;to[cnt]=y;value[cnt]=z;}void addedge2(int x,int y,int z){addedge(x,y,z);addedge(y,x,z);}void addedge2(int x,int y,int z,int xx){addedge(x,y,z);addedge(y,x,xx);}};#endifconst int maxn=200001,maxm=200002;/////////////////variables&functions////////////////////int n,m,v[maxn],nn,vv[maxn];map <int,int> mm;struct node{node *l,*r;int value;node():l(0),r(0),value(0){}node(node *ll,node *rr):l(ll),r(rr),value((l?l->value:0)+(r?r->value:0)){}node(node *ll,node *rr,int vv):l(ll),r(rr),value(vv){}node(int vv):l(0),r(0),value(vv){}};char ___[maxn*30*sizeof(node)];char *____=___;inline void *myalloc(size_t size){return (____+=size)-size;}#define newnode new (myalloc(sizeof(node))) node#define getll(x) (x?(x->l?x->l->value:0):0)#define getl(x) (x?x->l:0)#define getr(x) (x?x->r:0)struct Chairman_Tree{node *root[maxn];node *insert(node *x,int k,int L=1,int R=nn){if (L==R) return newnode(x?x->value+1:1);int mid=(L+R)>>1;if (k<=mid) return newnode(insert(getl(x),k,L,mid),getr(x));else return newnode(getl(x),insert(getr(x),k,mid+1,R));}int query(node *x,node *y,node *anc,node *ancc,int k,int L=1,int R=nn){if (L==R) return L;int mid=(L+R)>>1;int ll=getll(x)+getll(y)-getll(anc)-getll(ancc);if (k<=ll) return query(getl(x),getl(y),getl(anc),getl(ancc),k,L,mid);else return query(getr(x),getr(y),getr(anc),getr(ancc),k-ll,mid+1,R);}int query(node *x,node *y,node *anc,int k,int L=1,int R=nn){if (L==R) return L;int mid=(L+R)>>1;int ll=getll(x)+getll(y)-getll(anc);if (k<=ll) return query(getl(x),getl(y),getl(anc),k,L,mid);else return query(getr(x),getr(y),getr(anc),k-ll,mid+1,R);}inline int query(int x,int y,int anc,int ancc,int k){if (anc!=ancc) return query(root[x],root[y],root[anc],root[ancc],k);else return query(root[x],root[y],root[anc],k);}}seg;struct TREE{int next[maxm],first[maxn],to[maxm],cnt,aa[maxm],cna,fa[maxn];int rmq[maxm][21],ff[maxn],depth[maxn],rmqq[maxm][21];void addedge(int x,int y){next[++cnt]=first[x];first[x]=cnt;to[cnt]=y;}void addedge2(int x,int y){addedge(x,y);addedge(y,x);}void dfs(int x,int previous,int step){seg.root[x]=seg.insert(seg.root[previous],v[x]);aa[++cna]=x;depth[x]=step;if (!ff[x]) ff[x]=cna;for (int q=first[x];q;q=next[q]) if (to[q]!=previous){fa[to[q]]=x;// seg.root[to[q]]=seg.insert(seg.root[x],v[x]);dfs(to[q],x,step+1);aa[++cna]=x;}}void initrmq(){rep(i,1,cna) {rmq[i][0]=depth[aa[i]];rmqq[i][0]=aa[i];}rep(j,1,log2(cna)+1)for (int i=1;i<=cna+1-(1<<(j-1));++i){rmq[i][j]=rmq[i][j-1];rmqq[i][j]=rmqq[i][j-1];if (rmq[i][j]>rmq[i+(1<<(j-1))][j-1]) {rmq[i][j]=rmq[i+(1<<(j-1))][j-1];rmqq[i][j]=rmqq[i+(1<<(j-1))][j-1];}}}int lca(int x,int y){if (x==y) return x;int l=ff[x],r=ff[y],k;if (l==r) return rmq[l][0];if (l>r) swap(l,r);k=log2(r-l+1);if (rmq[l][k]>rmq[r-(1<<k)+1][k]) return rmqq[r-(1<<k)+1][k];else return rmqq[l][k];}}tree;int main(){read(n,m);rep(i,1,n) {read(v[i]);vv[i]=v[i];}sort(vv+1,vv+1+n);nn=unique(vv+1,vv+1+n)-vv-1;rep(i,1,nn) mm[vv[i]]=i;rep(i,1,n) v[i]=mm[v[i]];rep(i,1,n-1){int x,y;read(x,y);tree.addedge2(x,y);}tree.fa[1]=1;seg.root[0]=newnode();// seg.root[1]=seg.insert(seg.root[0],v[1]);tree.dfs(1,0,1);tree.initrmq();int lastans=0;rep(i,1,m){int u,v,k;read(u,v,k);u^=lastans;int temp=tree.lca(u,v);printf("%d",lastans=vv[seg.query(u,v,temp,tree.fa[temp],k)]);if (i!=m) putchar('\n');}return 0;}