8.19

8.16/M-PairsFormingLCM/Readme.md

@@ -11,4 +11,4 @@ ans=ans/2+1;(i<=j,
 ### 易错点
 * 
 ### 工具箱
-* 
+* https://www.cnblogs.com/shentr/p/5285407.html

Template/main.cpp

@@ -4,6 +4,10 @@
 #include <cmath>
 using namespace std;
 const int N=1e8+5;
+void initialise(int n)
+{
+	
+}
 int main()
 {
     int t;
@@ -13,6 +17,7 @@ int main()
     while(t--)
     {
         scanf("%d",&n);
+        initialise(n);
         for(int i=1;i<=n; i++)
         {
 

新建文件夹/A - Bottom.cpp

@@ -0,0 +1,113 @@
+#include<cstdio>
+#include<string.h>
+#include<algorithm>
+using namespace std;
+const int N=5e3+5,NN=N*N;
+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 ans[N];
+int len;
+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=0;
+	len=0;
+	memset(b,0,sizeof(bool)*(n+1));
+	memset(no,0,sizeof(bool)*(n+1));
+	memset(h,0,sizeof(int)*(n+1));
+}
+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];
+		if(!dfn[v])
+		{
+			tarjan(v);
+			low[u]=low[u]<low[v]? low[u]:low[v];
+		}
+		else
+		{
+			low[u]=low[u]<dfn[v]? low[u]:dfn[v];
+		}
+	}
+	if(low[u]==dfn[u])
+	{
+		id++;
+		now=s[top];
+		while(dfn[now]!=low[now])
+		{
+			nid[now]=id;
+			now=s[--top];
+			b[now]=0;
+		}
+		b[u]=0;
+		nid[u]=id;
+	}
+}
+int main()
+{
+	int u,v;
+	while(~scanf("%d",&n)&&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);
+		}
+		tarjan(0);
+		for(int i=1; i<=n; i++)
+		{
+			for(int j=h[i]; j; j=ne[j])
+			{
+				v=to[j];
+				if(nid[v]!=nid[i])
+				{
+					no[nid[i]]=1;
+					break;
+				}
+			}
+		}
+
+		for(int j=1; j<=n; j++)
+		{
+			if(!no[nid[j]])
+			{
+				printf("%d ",j);
+			}
+		}
+		printf("\n");
+	}
+	return 0;
+}

新建文件夹/D - Cross Swapping.cpp

@@ -0,0 +1,94 @@
+#include<cstdio>
+#include<string.h>
+#include<iostream>
+using namespace std;
+const int N=1e3+5;
+int a[N][N];
+bool b[N];
+int n;
+bool cmp(int k)
+{
+	for(int i=1;i<k;i++)
+	{
+		if(a[k][i]>a[i][k])
+		{
+//		printf("%d(i xiao):%d %d\n",k,i,0^b[i]);
+			return 0^b[i];
+		}
+		else if(a[k][i]<a[i][k])
+		{
+//			printf("%d(i big):%d %d\n",k,i,1^b[i]);
+			return 1^b[i];
+		}
+	}
+	for(int i=k+1;i<=n;i++)
+	{
+		if(a[k][i]<a[i][k])
+		{
+//		printf("%d(i xiao):%d %d\n",k,i,0^b[i]);
+			return 0^b[i];
+		}
+		else if(a[k][i]>a[i][k])
+		{
+//			printf("%d(i big):%d %d\n",k,i,1^b[i]);
+			return 1^b[i];
+		}
+	}
+	return 0;
+}
+int main()
+{
+	int t;
+	int k;
+	scanf("%d",&t);
+	while(t--)
+	{
+		scanf("%d",&n);
+		memset(b,0,sizeof(bool)*(n+1));
+		for(int i=1; i<=n; i++)
+		{
+			for(int j=1; j<=n; j++)
+			{
+				scanf("%d",&a[i][j]);
+//				a[i][j]=(i-1)*n+j;
+//				printf("%02d ",a[i][j]);
+			}
+//			printf("\n");
+		}
+		for(k=2; k<=n; k++)
+		{
+			if(a[k][1]<a[1][k])
+			{
+				b[k]=1;
+			}			
+		}
+		for(k=2; k<=n; k++)
+		{
+			if(!b[k])
+			{
+				if(cmp(k))
+				b[k]=1;
+			}
+		}
+		for(k=2; k<=n; k++)
+		{
+			if(b[k])
+			{
+				for(int i=1;i<=n;i++)
+				{
+					int tmp=a[k][i];
+					a[k][i]=a[i][k];
+					a[i][k]=tmp;
+				}
+			}
+		}
+		for(int i=1; i<=n; i++)
+		{
+			for(int j=1; j<=n; j++)
+			{
+				printf("%d ",a[i][j]);
+			}
+			printf("\n");
+		}
+	}
+}