8.20

8.19/A-Bottom.cpp

@@ -1,3 +1,4 @@
+//https://blog.csdn.net/anvt77205/article/details/102208781
 #include<cstdio>
 #include<string.h>
 #include<algorithm>
@@ -15,8 +16,6 @@ int id;
 int nid[N];
 int now;
 bool no[N];
-int ans[N];
-int len;
 void add(int u,int v)
 {
 	to[++cnt]=v;
@@ -29,14 +28,14 @@ void initialise(int n)
 	tot=0;
 	top=0;
 	id=0;
-	len=0;
 	memset(b,0,sizeof(bool)*(n+1));
 	memset(no,0,sizeof(bool)*(n+1));
 	memset(h,0,sizeof(int)*(n+1));
+	memset(dfn,0,sizeof(int)*(n+1));//WA 根据它判断有无经过 
 }
 void tarjan(int u)
 {
-//	printf("%d ",u);
+//	printf("%d:",u);
 	int v;
 	dfn[u]=++tot;
 	low[u]=tot;
@@ -45,12 +44,13 @@ void tarjan(int u)
 	for(int i=h[u]; i; i=ne[i])
 	{
 		v=to[i];
+//		printf("%d ",v);
 		if(!dfn[v])
 		{
 			tarjan(v);
 			low[u]=low[u]<low[v]? low[u]:low[v];
 		}
-		else
+		else if(b[v])
 		{
 			low[u]=low[u]<dfn[v]? low[u]:dfn[v];
 		}
@@ -58,16 +58,28 @@ void tarjan(int u)
 	if(low[u]==dfn[u])
 	{
 		id++;
-		now=s[top];
-		while(dfn[now]!=low[now])
+		do
 		{
-			nid[now]=id;
-			now=s[--top];
-			b[now]=0;
+			nid[s[top]]=id;
+			b[s[top]]=0;
 		}
-		b[u]=0;
-		nid[u]=id;
+		while(s[top--]!=u&&top>0);
+//		printf("\n\n");
 	}
+	// if(low[u]==dfn[u])
+	// {
+	// 	id++;
+	// 	now=s[top];
+	// 	while(dfn[now]!=low[now])
+	// 	{
+	// 		nid[now]=id;
+	// 		now=s[--top];
+	// 		b[now]=0;
+	// 	}
+	// 	top--;
+	// 	b[u]=0;
+	// 	nid[u]=id;
+	// }
 }
 int main()
 {
@@ -81,11 +93,15 @@ int main()
 			scanf("%d%d",&u,&v);
 			add(u,v);
 		}
-		//一开始放在前面，忽略了没有边的情况 
-		for(int i=1;i<=n;i++)
+		//一开始放在前面，忽略了没有边的情况
+		for(int i=1; i<=n; i++)
 		{
 			add(0,i);
-		}
+//			if(!dfn[i])
+//			{
+//				tarjan(i);
+//			}
+		}		
 		tarjan(0);
 		for(int i=1; i<=n; i++)
 		{
@@ -94,12 +110,17 @@ int main()
 				v=to[j];
 				if(nid[v]!=nid[i])
 				{
+//					printf("no:(%d,%d) ",i,v);
 					no[nid[i]]=1;
 					break;
 				}
 			}
 		}
-
+//		for(int j=1; j<=n; j++)
+//		{
+//			printf("nid[%d]=%d:%d ",j,nid[j],no[nid[j]]);
+//		}
+//		printf("\n");
 		for(int j=1; j<=n; j++)
 		{
 			if(!no[nid[j]])

8.19/A-Bottomreference.cpp

@@ -0,0 +1,93 @@
+// ´Þ¶«Ðñ 46ms
+#include<cstdio>
+using namespace std;
+struct edge
+{
+	int to,nxt;
+};
+int fmin(int a,int b)
+{
+	return a<b? a:b;
+}
+edge a[10000010];
+int n,e,cnt,head[50010],belong[50010],out[50010];
+int stack[50010],s_head,dnf[50010],low[50010],visit,newp;
+int vis[50010];
+void add(int x,int y)
+{
+	a[++cnt].to=y;
+	a[cnt].nxt=head[x];
+	head[x]=cnt;
+}
+void tarjan(int now)
+{
+	int tx,ty;
+	dnf[now]=low[now]=++visit;
+	stack[++s_head]=now;
+	vis[now]=1;
+	for(tx=head[now]; tx; tx=a[tx].nxt)
+	{
+		ty=a[tx].to;
+		if(vis[ty]==0)
+		{
+			tarjan(ty);
+			low[now]=fmin(low[now],low[ty]);
+		}
+		if(vis[now]==1)
+		{
+			low[now]=fmin(low[now],low[ty]);
+		}
+	}
+	if(low[now]==dnf[now])
+	{
+		newp++;
+		while(stack[s_head]!=now)
+		{
+			vis[stack[s_head]]=2;
+			belong[stack[s_head--]]=newp;
+		}
+		vis[stack[s_head]]=2;
+		belong[stack[s_head--]]=newp;
+	}
+	return;
+}
+void work(int now)
+{
+	int tx,ty;
+	for(tx=head[now]; tx; tx=a[tx].nxt)
+	{
+		ty=a[tx].to;
+		if(belong[now]!=belong[ty]) out[belong[now]]++;
+	}
+	return;
+}
+int main()
+{
+//    freopen("1.txt","r",stdin);
+//    freopen("2.txt","w",stdout);
+	int tx,ty;
+	while(1)
+	{
+		scanf("%d",&n);
+		if(n==0) break;
+		scanf("%d",&e);
+		for(int i=1; i<=e; i++)
+		{
+			scanf("%d%d",&tx,&ty);
+			add(tx,ty);
+		}
+		for(int i=1; i<=n; i++)
+		{
+			if(vis[i]==0) tarjan(i);
+		}
+		for(int i=1; i<=n; i++) work(i);
+		for(int i=1; i<=n; i++)
+		{
+			if(out[belong[i]]==0) printf("%d ",i);
+		}
+		printf("\n");
+		for(int i=1; i<=n; i++) head[i]=belong[i]=out[i]=vis[i]=0;
+		cnt=newp=visit=0;
+	}
+	return 0;
+}

8.19/C-kill.cpp

@@ -0,0 +1,156 @@
+#include<cstdio>
+#include<string.h>
+#include<algorithm>
+#include<vector>
+using namespace std;
+const int N=1e5+5,NN=3e5+5;
+int n,e;
+int to[NN],ne[NN];
+int h[N];
+int dfn[N],low[N];
+bool b[N];
+int s[N];//stack
+int cnt;
+int tot,top;
+int id;
+int nid[N];
+int now;
+bool no[N];
+int fa[N];
+vector<int> tfa[N];
+void add(int u,int v)
+{
+	to[++cnt]=v;
+	ne[cnt]=h[u];
+	h[u]=cnt;
+}
+void initialise(int n)
+{
+	cnt=0;
+	tot=0;
+	top=0;
+	id=n;
+	memset(b,0,sizeof(bool)*(n+1));
+	memset(no,0,sizeof(bool)*(n+1));
+	memset(h,0,sizeof(int)*(n+1));
+	memset(dfn,0,sizeof(int)*(n+1));//WA 根据它判断有无经过
+}
+void tarjan(int u)
+{
+//	printf("%d:",u);
+	int v;
+	dfn[u]=++tot;
+	low[u]=tot;
+	s[++top]=u;
+	b[u]=1;
+	for(int i=h[u]; i; i=ne[i])
+	{
+		v=to[i];
+//		printf("%d ",v);
+		if(!dfn[v])
+		{
+			tarjan(v);
+			low[u]=low[u]<low[v]? low[u]:low[v];
+		}
+		else if(b[v])
+		{
+			low[u]=low[u]<dfn[v]? low[u]:dfn[v];
+		}
+	}
+	if(low[u]==dfn[u])
+	{
+		id++;
+//		printf("(%d):",id);
+		do
+		{
+//			printf("%d ",s[top]);
+			nid[s[top]]=id;
+			b[s[top]]=0;
+		}
+		while(s[top--]!=u&&top>0);
+//		printf("\n");
+	}
+}
+void dfs(int u,int fat)
+{
+	for(int i=h[u]; i; i=ne[i])
+	{
+		int v=to[i];
+		tfa[v].push_back(fat);
+		dfs(v,fat);//这句居然没写 
+	}
+}
+int main()
+{
+	int u,v;
+//	while(~scanf("%d",&n)&&n)
+//	{
+		scanf("%d",&n);
+		initialise(n);
+		scanf("%d",&e);
+		for(int i=1; i<=e; i++)
+		{
+			scanf("%d%d",&u,&v);
+			add(u,v);
+		}
+		//一开始放在前面，忽略了没有边的情况
+		for(int i=1; i<=n; i++)
+		{
+//			add(0,i);
+			if(!dfn[i])
+			{
+				tarjan(i);
+			}
+		}
+//		tarjan(0);
+		int l=cnt+1;
+		for(int i=1; i<=n; i++)
+		{
+			for(int j=h[i]; j; j=ne[j])
+			{
+				v=to[j];
+				if(nid[v]!=nid[i])
+				{
+					add(nid[i],nid[v]);
+					fa[nid[v]]++;
+//					printf("(%d)to(%d)%d\n",nid[i],nid[v],fa[nid[v]]);
+				}
+			}
+		}
+		int ans=0;
+		for(int i=n+1; i<=id; i++)
+		{
+//			printf("(%d)",i);
+			if(fa[i]==0 )
+			{
+				ans++;
+				dfs(i,i);
+			}
+		}
+//		printf("%d        ",ans);
+		bool des=0;
+		for(int i=n+1; i<=id; i++)
+		{
+			if(fa[i]==0 )
+			{
+				int j=h[i];//i ->u
+				for(; j; j=ne[j])
+				{
+					v=to[j];
+//					printf("%d to %d:%d\n",i,v,tfa[v].size());
+					if(tfa[v].size()==1)
+					{
+						break;
+					}
+				}
+				if(!j)
+				{
+					des=1;
+					break;
+				}
+			}
+		}
+		printf("%.6lf",1.0-(ans-des)*1.0/n);
+//	}
+	return 0;
+}

8.19/C-killreference.cpp

@@ -0,0 +1,95 @@
+#include<stdio.h>
+#include<string.h>
+#include<stdlib.h>
+#include<algorithm>
+#include<iostream>
+#include<vector>
+#include<queue>
+using namespace std;
+#define MAXN 100001
+#define MAXM 300001
+struct people
+{
+	int to,next,from;
+};
+people a[MAXM];
+int N,M,last[MAXN],step=0,tot1=0,tot=0,LOW[MAXN],DFN[MAXN],stack[MAXN],ans=0;
+int belong[MAXN],indegree[MAXN],IN,OUT,ans1=0,size1[MAXN],ans2=0;
+bool instack[MAXN];
+void add(int x,int y)
+{
+	a[++tot].to=y;
+	a[tot].from=x;
+	a[tot].next=last[x];
+	last[x]=tot;
+}
+void Tarjan(int now)
+{
+	DFN[now]=LOW[now]=++step;
+	stack[++tot1]=now;
+	instack[now]=true;
+	for(int i=last[now]; i; i=a[i].next)
+	{
+		int now_to=a[i].to;
+		if(!DFN[now_to])
+		{
+			Tarjan(now_to);
+			LOW[now]=min(LOW[now_to],LOW[now]);
+		}
+		else if(instack[now_to])
+			LOW[now]=min(DFN[now_to],LOW[now]);
+	}
+
+	if(DFN[now]==LOW[now])
+	{
+		int now_out;
+		ans++;
+		do
+		{
+			now_out=stack[tot1--];
+			instack[now_out]=false;
+			belong[now_out]=ans;
+			size1[ans]++;
+		}
+		while(now_out!=now);
+	}
+}
+int main()
+{
+//	freopen("input.in","r",stdin);
+//	freopen("output.out","w",stdout);
+	memset(belong,0,sizeof(belong));
+	memset(DFN,0,sizeof(DFN));
+	memset(LOW,0,sizeof(LOW));
+	memset(last,0,sizeof(last));
+	memset(instack,false,sizeof(instack));
+	scanf("%d%d",&N,&M);
+	for(int i=1; i<=M; i++)
+	{
+		int A,B;
+		scanf("%d%d",&A,&B);
+		add(A,B);
+	}
+	for(int i=1; i<=N; i++)
+		if(!DFN[i])
+			Tarjan(i);
+	for(int i=1; i<=tot; i++)
+	{
+		if(belong[a[i].to]!=belong[a[i].from])
+			indegree[belong[a[i].to]]++;
+	}
+
+	for(int i=1; i<=ans; i++)
+		if(!indegree[i])
+			ans1++;
+	if(ans1>1)
+		for(int i=1; i<=ans; i++)
+			if(!indegree[i] && size1[i]==1)
+			{
+				ans1--;
+				break;
+			}
+	printf("%.6lf\n",1-(double)ans1/N);
+	//system("pause");
+	return 0;
+}

8.19/tempCodeRunnerFile.cpp

@@ -0,0 +1,7 @@
+[top];
+		while(now!=u)
+		{
+			nid[now]=id;
+			now=s[--top];
+			b[now]=0;
+		}

8.20/A.cpp

@@ -0,0 +1,33 @@
+#include <iostream>
+#include<cstdio>
+#include<algorithm>
+#include <cmath>
+using namespace std;
+const int N=1e5+5;
+void init(int n)
+{
+	
+}
+int main()
+{
+    int t;
+    int t1=0;
+    int n;
+    scanf("%d",&t);
+    while(t--)
+    {
+        scanf("%d",&n);
+        init(n);
+        for(int i=1;i<=n; i++)
+        {
+			for(int j=1;j<=n;j++)
+			{
+				int z=(i&j)+(i|j);
+			printf("%d,%d:%d\n",i,j,z);
+			}
+        }
+        printf("Case %d: %d\n",++t1,n);
+    }
+    return 0;
+}
+

8.20/B.cpp

@@ -0,0 +1,183 @@
+#include <iostream>
+#include<cstdio>
+#include<algorithm>
+#include <cmath>
+#include<cstring>
+using namespace std;
+const int N=1e6+5;
+char s[N],sub[N];
+int a[11]= {0};
+int l[N];
+int su[N];
+int cnt;
+int sublen;
+int len;
+//void init(int n)
+//{
+//
+//}
+void ce()
+{
+	printf("\n(%d)\n",len) ;
+	for(int i=0; i<10; i++)
+	{
+		printf("%d(%d) ",i,a[i]);
+	}
+	printf("\n");
+	for(int i=1; i<=cnt; i++)
+	{
+		printf("%d",l[i]);
+	}
+}
+bool cmp(int b)
+{
+	for(int i=0; i<sublen; i++)
+	{
+		if(su[i]>l[i+b])
+		{
+			return 0;
+		}
+		else if(su[i]<l[i+b])
+		{
+			return 1;
+		}
+	}
+	return 1;
+}
+//void useless()
+//{
+//	cnt=1;
+//	for(int i=0; i<=9; i++)
+//	{
+//		while(a[i])
+//		{
+//			a[i]--;
+//			l[++cnt]=i;
+////			break;//wrong
+//		}
+//	}
+//	for(int i=0; i<sublen; i++)
+//	{
+//		l[cnt+1+i]=su[i];
+//	}
+//	int i;
+//	for(i=1; i<=cnt; i++)
+//	{
+//		if(cmp(i))
+//		{
+//			break;
+//		}
+//		printf("%d",l[i]);
+//	}
+//	printf("%s",sub);
+//	for(; i<=cnt; i++)
+//	{
+//		printf("%d",l[i]);
+//	}
+//}
+int wei(int n)
+{
+	int sum=0;
+	int len=n;
+	while(len>0)
+	{
+		sum++;
+		len/=10;
+	}
+	int len2=n-sum;
+	int sum2=0;
+	while(len2>0)
+	{
+		sum2++;
+		len2/=10;
+	}
+	if(sum==sum2)
+	{
+		return n-sum;
+	}
+	else
+	{
+		return n-sum+1;
+	}
+}
+bool ling()
+{
+	for(int i=1;i<sublen;i++)
+	{
+		if(su[i]>0)
+		{
+			return 0;
+		}
+	}
+	return 1;
+}
+int main()
+{
+	scanf("%s%s",&s,&sub);
+	len=strlen(s);
+	for(int i=0; i<len; i++)
+	{
+		a[s[i]-'0']++;
+	}
+	len=wei(len);
+	int y=len;
+	while(y>0)
+	{
+		a[y%10]--;
+		y/=10;
+	}
+	sublen=strlen(sub);
+	bool fir=1;
+	for(int i=0; i<sublen; i++)
+	{
+		su[i]=sub[i]-'0';
+		a[su[i]]--;
+	}
+	int now=0;
+	while(su[0]==su[now]&&now<sublen-2)
+	{
+		now++;
+		if(su[0]!=su[now])
+		{
+			fir=su[now]<su[0];
+		}
+	}
+	
+	bool vis=0;
+	if(a[0]||su[0]==0)
+	for(int i=1; i<=9; i++)
+	{
+		if(a[i])
+		{
+			if(su[0]!=0&&su[0]<=i&&(su[0]<i||ling()))//i->a[i]
+			{
+				vis=1;
+				printf("%s",sub);
+				break;
+			}
+			a[i]--;
+			printf("%d",i);
+			break;
+		}
+	}
+	for(int i=0; i<=9; i++)
+	{
+		if(!vis&&su[0]==i&&fir)
+		{
+			printf("%s",sub);
+		}
+		while(a[i])
+		{
+			printf("%d",i);
+			a[i]--;
+		}
+		if(!vis&&su[0]==i&&!fir)
+		{
+			printf("%s",sub);
+		}
+	}
+
+//	ce();
+	return 0;
+}
+

8.20/C.cpp

@@ -0,0 +1,68 @@
+#include<cstdio>
+#include<vector>
+using namespace std;
+const int N=2e5+5,inf=0x3f3f3f3f;
+int w[N],to[N],ne[N],h[N];
+int cnt=0;
+int n;
+struct Node
+{
+	int fa;
+	int sum;
+	int max;
+	int min;
+	int len;
+//	vector<int> son;
+} a[N];
+void add(int u,int v,int w1)
+{
+	a[v].fa=u;
+	w[++cnt]=w1;
+	to[cnt]=v;
+	ne[cnt]=h[u];
+	h[u]=cnt;
+}
+void dfs(int u)
+{
+	int v,vmax;
+	a[u].max=0;
+	a[u].min=inf;
+	a[u].len=0;
+	for(int i=h[u]; i; i=ne[i])
+	{
+		v=to[i];
+		dfs(v);
+		a[u].sum+=a[v].sum+w[i]*(a[v].len+1);
+		vmax=a[v].max+w[i];
+		a[u].max=a[u].max>vmax? a[u].max:vmax;
+		a[u].min=a[u].min<w[i]? a[u].min:w[i];
+		a[u].len+=a[v].len+1;
+	}
+	if(a[u].min==inf)
+	{
+		a[u].min=0;
+	}
+//	if(a[u].len==0)
+//	{
+//		a[u].len=1;
+//	}
+}
+void ce()
+{
+	for(int i=1; i<=n; i++)
+	{
+		printf("%d:%d %d %d %d %d\n",i,a[i].fa ,a[i].max,a[i].min,a[i].sum,a[i].len );
+	}
+}
+int main()
+{
+	int u,v,w1;
+	scanf("%d",&n);
+	for(int i=2; i<=n; i++)
+	{
+		scanf("%d%d",&u,&w1);
+		add(u,i,w1);
+	}
+	dfs(1);
+	ce();
+}