delete pics to save space

5.1203B.cpp

@@ -0,0 +1,86 @@
+#include<cstdio>
+struct char_reader
+{
+	FILE* f;
+	char *buf,*p1,*p2;
+	int size;
+	char_reader(FILE* fin,int bufsize=100000)
+	{
+		f=fin;
+		size=bufsize;
+		p1=p2=0;
+		buf=new char[bufsize];
+	}
+	inline int operator()()
+	{
+		return p1==p2&&(p2=(p1=buf)+fread(buf,1,size,f),p1==p2)?EOF:*p1++;
+	}
+};
+struct char_writer
+{
+	FILE* f;
+	char *buf,*p,*end;
+	char_writer(FILE* fout,int bufsize=100000)
+	{
+		f=fout;
+		buf=new char[bufsize];
+		p=buf;
+		end=buf+bufsize;
+	}
+	~char_writer()
+	{
+		fwrite(buf,p-buf,1,f);
+	}
+	inline char operator()(char ch)
+	{
+		return end==p&&(fwrite(buf,end-buf,1,f),p=buf),*p++=ch;
+	}
+};
+char_reader gch(stdin);
+char_writer wch(stdout);
+template<typename T> inline void read(T& t)
+{
+	t=0; bool f=false; char ch;
+	while(ch=gch(),!((ch>='0'&&ch<='9')||ch=='-'));
+	if(ch=='-') f=true,ch=gch();
+	t=ch-'0';
+	while(ch=gch(),ch>='0'&&ch<='9') t=t*10+ch-'0';
+	if(f) t=-t;
+}
+#if __cplusplus >= 201103L
+template<typename T,typename... Args> inline void read(T& t,Args&... args) { read(t); read(args...); }
+#endif
+#include<cstring>
+#include<algorithm>
+#include<map>
+using namespace std;
+int T,n,a[205],cnt;
+int main()
+{
+	#ifdef local
+	freopen("pro.in","r",stdin);
+	#endif
+	read(T);
+	while(T-->0)
+	{
+		read(n);
+		map<int,int> mp;
+		for(int i=0;i<n*4;i++)
+		{
+			int x; read(x);
+			mp[x]++;
+		}
+		cnt=0;
+		for(auto v:mp)
+		{
+			if(v.second&1) { puts("NO"); goto ed; }
+			for(int i=0;i<v.second/2;i++) a[cnt++]=v.first;
+		}
+		// printf("a: "); for(int i=0;i<cnt;i++) printf("%d ",a[i]); puts("");
+		for(int i=1,j=cnt-2;i<j;i++,j--)
+			if(a[i]*a[j]!=a[0]*a[cnt-1]) { puts("NO"); goto ed; }
+		puts("YES");
+		ed:;
+	}
+	return 0;
+}