Codeforces 136 divIID && zoj 3633 && HDU 4358

三道类似的线段树

可参见这里的代码

http://blog.youkuaiyun.com/struggle_mind/article/details/7931956

今天下午把HDU 4358重敲了一遍

#include<cstdio>
#include<algorithm>
#include<cstring>
#include<vector>
#define N 100100
using namespace std;
int val[N],a[N];

int head[N],cnt,tim;
struct Edge{
    int v,next;
}edge[N*2];
int dep[N],son[N];

struct Query{
    int x,y,id;
}query[N];

struct Tree{
    int l,r,val;
}tree[3*N];

vector<int>vec[N];
int ans[N];

void init(){
    memset(head,-1,sizeof(head));
    cnt=tim=0;
}
void addedge(int u,int v){
    edge[cnt].v=v;
    edge[cnt].next=head[u];
    head[u]=cnt++;
    edge[cnt].v=u;
    edge[cnt].next=head[v];
    head[v]=cnt++;
}
void dfs(int u,int fa){
    int i;
    dep[u]=++tim,son[u]=1;
    for(i=head[u];i!=-1;i=edge[i].next){
        int v=edge[i].v;
        if(v==fa)continue;
        dfs(v,u);
        son[u]+=son[v];
    }
}

bool cmp(struct Query a,struct Query b){
    return a.y<b.y;
}

void build(int s,int t,int id){
    tree[id].l=s,tree[id].r=t,tree[id].val=0;
    if(s!=t){
        int mid=(s+t)>>1;
        build(s,mid,id<<1);
        build(mid+1,t,id<<1|1);
    }
}
void insert(int pos,int val,int id){
    if(tree[id].l==tree[id].r){
        tree[id].val=val;
        return ;
    }
    int mid=(tree[id].l+tree[id].r)>>1;
    if(mid>=pos)insert(pos,val,id<<1);
    else if(mid<pos)insert(pos,val,id<<1|1);
    tree[id].val=tree[id<<1].val+tree[id<<1|1].val;
}
int sea(int s,int t,int id){
    if(tree[id].l==tree[id].r)return tree[id].val;
    if(tree[id].l==s && tree[id].r==t)return tree[id].val;
    int mid=(tree[id].l+tree[id].r)>>1;
    if(mid>=t)return sea(s,t,id<<1);
    else if(mid<s)return sea(s,t,id<<1|1);
    else return sea(s,mid,id<<1)+sea(mid+1,t,id<<1|1);
}

int main(){
    int t,T,q;
    int n,k,kk;
    int i,j;
    int u,v;
    int tem;
    scanf("%d",&T);
    for(t=1;t<=T;t++){
        printf("Case #%d:\n",t);
        scanf("%d %d",&n,&k);
        //
        kk=0;
        for(i=1;i<=n;i++){
            scanf("%d",&val[i]);
            a[kk++]=val[i];
        }
        sort(a,a+kk);
        int nn=unique(a,a+kk)-a;
        //
        init();
        for(i=1;i<n;i++){
            scanf("%d %d",&u,&v);
            addedge(u,v);
        }
        dfs(1,0);
        //
        scanf("%d",&q);
        for(i=1;i<=q;i++){
            scanf("%d",&tem);
            query[i].x=dep[tem];
            query[i].y=dep[tem]+son[tem]-1;
            query[i].id=i;
        }
        sort(query+1,query+1+q,cmp);
        //
        build(1,tim,1);
        for(i=0;i<nn;i++)vec[i].clear();
        kk=1;
        for(i=1;i<=n;i++){
            int u=lower_bound(a,a+nn,val[dep[i]])-a;
            if(vec[u].size()<k){
                vec[u].push_back(i);
                if(vec[u].size()==k)
                    insert(vec[u][0],1,1);
            }
            else if(vec[u].size()>=k){
                vec[u].push_back(i);
                insert(vec[u][vec[u].size()-k-1],-1,1);
                insert(vec[u][vec[u].size()-k],1,1);
                if(vec[u].size()>k+1)
                    insert(vec[u][vec[u].size()-k-2],0,1);
            }
            while(kk<=q && query[kk].y==i){
                ans[query[kk].id]=sea(query[kk].x,query[kk].y,1);
                kk++;
            }
            if(kk==q+1)break;
        }
        for(i=1;i<=q;i++)printf("%d\n",ans[i]);
        if(t!=T)puts("");
    }
    return 0;
}