delete pics to save space

2.10129.cpp

@@ -0,0 +1,77 @@
+#include<cstdio>
+#include<cstring>
+#include<cmath>
+using namespace std;
+int fa[30];
+int ff(int x)
+{
+	int a,b;
+	a=x;
+	while(x!=fa[x]) x=fa[x];
+	while(a!=x)
+	{
+		b=fa[a];
+		fa[a]=x;
+		a=b;
+	}
+	return x;
+}
+int rd[30],cd[30],n;
+char str[1005];
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	int T;
+	bool f1,f2;
+	scanf("%d",&T);
+	while(T-->0)
+	{
+		scanf("%d",&n);
+		memset(rd,0,sizeof(rd));
+		memset(cd,0,sizeof(cd));
+		for(int i=0;i<26;i++) fa[i]=i;
+		for(int i=0;i<n;i++)
+		{
+			scanf("%s",str);
+			int len=strlen(str);
+			rd[str[len-1]-'a']++;
+			cd[str[0]-'a']++;
+			if(ff(str[0]-'a')!=ff(str[len-1]-'a'))
+				fa[ff(str[0]-'a')]=ff(str[len-1]-'a');
+		}
+		for(int i=1;i<26;i++)
+			if((rd[i]||cd[i])&&ff(i)!=ff(0))
+			{
+				printf("The door cannot be opened.\n");
+				goto next;
+			}
+		f1=f2=0;
+		for(int i=0;i<26;i++)
+			if(rd[i]||cd[i])
+			{
+				if(abs(rd[i]-cd[i]>1))
+				{
+					printf("The door cannot be opened.\n");
+					goto next;
+				}
+				if(rd[i]-cd[i]==1) f1=1;
+				if(cd[i]-rd[i]==1) f2=1;
+			}
+		if(f1==f2)
+		{
+			printf("Ordering is possible.\n");
+			goto next;
+		}
+		
+next:
+		continue;
+	}
+	return 0;
+}
+/*
+The door cannot be opened.
+Ordering is possible.
+The door cannot be opened.
+*/