delete pics to save space

history_source/ccf 基础篇/U6/6.5.1.cpp

@@ -0,0 +1,168 @@
+#include<iostream>
+using namespace std;
+struct con
+{
+	int a,b;
+};
+con *cont;int len;
+template<class T_fsort>
+void fsort(T_fsort *left,T_fsort *right,bool (*cmp)(T_fsort a,T_fsort b),T_fsort *k)
+{
+	if(right-left<=1) return;
+	unsigned int len=right-left;
+	fsort(left,left+len/2,cmp,k);
+	fsort(left+len/2,right,cmp,k+len/2);
+	int i=0,j=len/2,n=0;
+	while(i<len/2&&j<len)
+	{
+		if(cmp(left[i],left[j])) k[n++]=left[i++];
+		else k[n++]=left[j++];
+	}
+	while(i<len/2) k[n++]=left[i++];
+	while(j<len) k[n++]=left[j++];
+	for(int i=0;i<len;i++) left[i]=k[i];
+}
+template<class Tb_fsort>
+void fsort(Tb_fsort *left,Tb_fsort *right,bool (*cmp)(Tb_fsort a,Tb_fsort b))
+{
+	if(right-left<=1) return;
+	unsigned int len=right-left;
+	Tb_fsort k[len];
+	fsort(left,right,cmp,k);
+}
+bool cmp(con a,con b)
+{
+	if(a.a<b.a) return 1;
+	if(a.a>b.a) return 0;
+	return a.b<b.b;
+}
+con* road(int a)
+{
+	con *left,*right,*mid;
+	left=cont;
+	right=cont+len;
+	while(left<right)
+	{
+		mid=left+(right-left)/2;
+		if(mid->a>a) right=mid;
+		if(mid->a<a) left=mid;
+		if(mid->a==a)
+		{
+			left=mid;
+			break;
+		}
+	}
+	if(left->a!=a) return 0;
+	while(left>=cont&&left->a==a) left--;
+	left++;
+	return left;
+}
+template<class T_queue>
+struct Node_queue
+{
+	T_queue num;
+	Node_queue *next;
+};
+template<class a_queue>
+struct queue
+{
+	Node_queue<a_queue> *head,*tail;
+	int SIZE_queue;
+	void beginning()
+	{
+		head=tail=new Node_queue<a_queue>;
+		tail->next=head;
+		SIZE_queue=0;
+	}
+	bool push(a_queue s)
+	{
+		SIZE_queue++;
+		tail->num=s;
+		if(tail->next==head)
+		{
+			tail->next=new Node_queue<a_queue>;
+			tail->next->next=head;
+			tail=tail->next;
+			return 1;
+		}
+		tail=tail->next;
+		return 0;
+	}
+	bool pop()
+	{
+		if(head==tail) return 1;
+		head=head->next;
+		SIZE_queue--;
+		return 0;
+	} 
+	a_queue front()
+	{
+		return head->num;
+	} 
+	int size()
+	{
+		return SIZE_queue;
+	}
+};
+struct BFS
+{
+	int num;
+	int step;
+};
+int main()
+{
+	int n,m,p;
+	ios::sync_with_stdio(0);
+	cin>>n>>m>>p;
+	cont=new con[m*2+10];
+	con* x;
+	int u,v;
+	for(int i=0;i<m;i++)
+	{
+		cin>>u>>v;
+		cont[len].a=u;
+		cont[len].b=v;
+		len++;
+		cont[len].b=u;
+		cont[len].a=v;
+		len++;
+	}
+	fsort(cont,cont+len,cmp);
+	bool guo[n+1]={0,1};
+	queue<BFS>bfs;
+	bfs.beginning();
+	BFS r;
+	r.num=1;
+	r.step=0;
+	bfs.push(r);
+	while(bfs.size()>0&&bfs.front().step<=p)
+	{
+		x=road(bfs.front().num);
+		if(x!=0)
+		{
+			while(x->a==bfs.front().num)
+			{
+				if(!guo[x->b]) 
+				{
+					r.num=x->b;
+					r.step=bfs.front().step+1;
+					bfs.push(r);
+					guo[x->b]=1;
+				}
+				x++;
+			}
+		}
+		bfs.pop();
+	}
+	int ans=0;
+	for(int i=0;i<n+1;i++) ans+=guo[i];
+	cout<<ans<<endl;
+	return 0;
+}
+/*
+4 4 2
+1 2
+1 3
+2 3
+3 4
+*/