[Pb_ds] [combined balancing tree heuristic] [Combined Query set] bzoj2733 [hnoi2012] yongwuxiang

Use and query sets to maintain connectivity. Maintain a balance tree for each connected block. Heuristic merge during merge. Relatively lazy. pb_ds is used.

 1 #include<cstdio> 2 #include<ext/pb_ds/assoc_container.hpp> 3 #include<ext/pb_ds/tree_policy.hpp> 4 using namespace std; 5 using namespace __gnu_cxx; 6 using namespace __gnu_pbds; 7 tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> T[100001]; 8 tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>::iterator it; 9 int num[100001],val[100001],fa[100001],rank[100001];10 int n,m,q,x,y,f1,f2;11 char op[2];12 int Res,Num;char C,CH[20];13 inline int G()14 {15     Res=0;C=‘*‘; 16     while(C<‘0‘||C>‘9‘)C=getchar();17     while(C>=‘0‘&&C<=‘9‘){Res=Res*10+(C-‘0‘);C=getchar();}18     return Res;19 }20 inline void P(int x)21 {22     Num=0;while(x>0)CH[++Num]=x%10,x/=10;23     while(Num)putchar(CH[Num--]+48);24     putchar(‘\n‘);25 }26 void init()27 {28     for(int i=1;i<=n;i++)29       fa[i]=i;30 }31 int findroot(int x) 32 {33     if(fa[x]==x)34       return x;35     int rt=findroot(fa[x]);36     fa[x]=rt;37     return rt;38 }39 void Union(const int &u,const int &v)40 {41     if(rank[u]<rank[v])42       {43           fa[u]=v;44           for(it=T[u].begin();it!=T[u].end();it++)45             T[v].insert((*it));46           T[u].clear();47       }48     else49       {50         fa[v]=u;51         for(it=T[v].begin();it!=T[v].end();it++)52             T[u].insert((*it));53           T[v].clear();54         if(rank[u]==rank[v]) rank[u]++;55       }56 }57 int main()58 {59     n=G();m=G();60     init();61     for(int i=1;i<=n;i++)62       {63           val[i]=G();64           T[i].insert(val[i]);65           num[val[i]]=i;66       }67     for(int i=1;i<=m;i++)68       {69           x=G();y=G();70           f1=findroot(x),f2=findroot(y);71           if(f1!=f2) Union(f1,f2);72       }73     q=G();74     for(int i=1;i<=q;i++)75       {76           scanf("%s",op);x=G();y=G();77           if(op[0]==‘Q‘)78             {79                 f1=findroot(x);80                 if(T[f1].size()<y) puts("-1");81                 else P(num[*T[f1].find_by_order(y-1)]);82             }83           else84             {85                 f1=findroot(x),f2=findroot(y);86               if(f1!=f2) Union(f1,f2);87             }88       }89     return 0;90 }

 

[Pb_ds] [combined balancing tree heuristic] [Combined Query set] bzoj2733 [hnoi2012] yongwuxiang