delete pics to save space

2.1479.cpp

@@ -0,0 +1,183 @@
+#include<cstdlib>
+struct Node
+{
+	Node *ch[2];
+	int r,v,s;
+	Node(int v):v(v) { ch[0]=ch[1]=NULL; r=rand(); s=1; }
+	inline bool operator<(const Node &b) const
+	{
+		return r<b.r;
+	}
+	inline int cmp(int x) const { return x==v?-1:x>=v; }
+	inline void maintain()
+	{
+		s=1+(ch[0]!=NULL?ch[0]->s:0)+(ch[1]!=NULL?ch[1]->s:0);
+	}
+};
+void rotate(Node* &o,int d)
+{
+	Node* k=o->ch[d^1];
+	o->ch[d^1]=k->ch[d];
+	k->ch[d]=o;
+	o->maintain();k->maintain();
+	o=k;
+}
+void insert(Node* &o,int x)
+{
+	if(o==NULL) o=new Node(x);
+	else
+	{
+		int d=(x < o->v ? 0 : 1);
+		insert(o->ch[d],x);
+		if(o->ch[d]->r > o->r) rotate(o,d^1);
+	}
+	o->maintain();
+}
+void remove(Node* &o,int x)
+{
+	int d=o->cmp(x);
+	if(d==-1)
+	{
+		Node* u=o;
+		if(o->ch[0]!=NULL&&o->ch[1]!=NULL)
+		{
+			int d2= (o->ch[0]->r > o->ch[1]->r ? 1: 0);
+			rotate(o,d2);
+			remove(o->ch[d2],x);
+		}
+		else
+		{
+			if(o->ch[0]==NULL) o=o->ch[1];
+			else o=o->ch[0];
+			delete u;
+		}
+	}
+	else remove(o->ch[d],x);
+	if(o!=NULL) o->maintain();
+}
+
+#include<cstdio>
+#include<cstring>
+#include<vector>
+using namespace std;
+const int maxcmd=500010;
+struct Command
+{
+	char type;
+	int x,p;
+} cmds[maxcmd];
+const int maxn=20010;
+const int maxm=60010;
+int n,m,w[maxn],f[maxm],t[maxm],rmvd[maxm];
+
+int fa[maxn];
+int ff(int x) { return fa[x]!=x?fa[x]=ff(fa[x]):x; }
+
+Node* root[maxn];
+
+int kth(Node *o,int k)
+{
+	if(o==NULL||k<=0||k > o->s) return 0;
+	int s=(o->ch[1]==NULL?0:o->ch[1]->s);
+	if(k==s+1) return o->v;
+	else if(k<=s) return kth(o->ch[1],k);
+	else return kth(o->ch[0],k-s-1);
+}
+void IstTree(Node* &src,Node* &dest)
+{
+	if(src->ch[0]!=NULL) IstTree(src->ch[0],dest);
+	if(src->ch[1]!=NULL) IstTree(src->ch[1],dest);
+	insert(dest,src->v);
+	delete src;
+	src=NULL;
+}
+void RmvTree(Node* &o)
+{
+	if(o->ch[0]!=NULL) RmvTree(o->ch[0]);
+	if(o->ch[1]!=NULL) RmvTree(o->ch[1]);
+	delete o;
+	o=NULL;
+}
+void AddEdge(int x)
+{
+	int u=ff(f[x]),v=ff(t[x]);
+	if(u!=v)
+	{
+		if(root[u]->s < root[v]->s)
+		{
+			fa[u]=v;
+			IstTree(root[u],root[v]);
+		}
+		else
+		{
+			fa[v]=u;
+			IstTree(root[v],root[u]);
+		}
+	}
+}
+
+int qcnt;
+long long qtot;
+void query(int x,int k)
+{
+	qcnt++;
+	qtot+=kth(root[ff(x)],k);
+}
+void ChangeWeight(int x,int v)
+{
+	int u=ff(x);
+	remove(root[u],w[x]);
+	insert(root[u],v);
+	w[x]=v;
+}
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	int kase=0;
+	while(scanf("%d%d",&n,&m)==2&&n)
+	{
+		for(int i=1;i<=n;i++) scanf("%d",&w[i]);
+		for(int i=1;i<=m;i++) scanf("%d%d",&f[i],&t[i]);
+		memset(rmvd,0,sizeof(rmvd));
+		
+		int c=0;
+		while(1)
+		{
+			char type;
+			int x,p=0,v=0;
+			scanf(" %c",&type);
+			if(type=='E') break;
+			scanf("%d",&x);
+			if(type=='D') rmvd[x]=true;
+			if(type=='Q') scanf("%d",&p);
+			if(type=='C')
+			{
+				scanf("%d",&v);
+				p=w[x];
+				w[x]=v;
+			}
+			cmds[c++]=(Command){type,x,p};
+		}
+		
+		for(int i=1;i<=n;i++)
+		{
+			fa[i]=i;
+			if(root[i]!=NULL) RmvTree(root[i]);
+			root[i]=new Node(w[i]);
+		}
+		for(int i=1;i<=m;i++)
+			if(!rmvd[i]) AddEdge(i);
+		
+		qtot=qcnt=0;
+		for(int i=c-1;i>=0;i--)
+		{
+			if(cmds[i].type=='D') AddEdge(cmds[i].x);
+			if(cmds[i].type=='Q') query(cmds[i].x,cmds[i].p);
+			if(cmds[i].type=='C') ChangeWeight(cmds[i].x,cmds[i].p);
+		}
+		printf("Case %d: %.6lf\n",++kase,qtot/(double)qcnt);
+	}
+	return 0;
+}