delete pics to save space

history_source/信息学奥赛一本通/3.4.3.5.cpp

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+#include<cstdio>
+#include<cstring>
+#define maxn 100000
+struct node
+{
+	int id;
+	long long step;
+};
+int *tu[maxn+1],num[maxn+1],n,p,c,i,j,a,b,head,tail;
+long long m;
+node queue[maxn+5];
+char mem[maxn/8+5];
+bool r(int idx)
+{
+	return mem[idx/8]&(1<<(idx%8));
+}
+int w(int idx,int v)
+{
+	mem[idx/8]&=~(1<<(idx%8));
+	mem[idx/8]|=1<<(idx%8);
+	return v;
+}
+inline char get()
+{
+	static char ch;
+	fread(&ch,1,1,stdin);
+	return ch;
+}
+inline long long read()
+{
+	static long long a;
+	static char ch;
+	a=0;
+	while(ch=get(),!(ch>='0'&&ch<='9'));
+	a=ch-'0';
+	while(ch=get(),ch>='0'&&ch<='9') a=a*10+ch-'0';
+	return a;
+}
+int main()
+{
+	freopen("candy.in","rb",stdin);
+	freopen("candy.out","w",stdout);
+	n=read();p=read();c=read();
+	m=read();
+	for(i=0;i<p;i++)
+	{
+		a=read();b=read();
+		num[a]++;
+		num[b]++;
+	}
+	freopen("candy.in","rb",stdin);
+	for(i=1;i<=n;i++) tu[i]=new int[num[i]];
+	n=read();p=read();c=read();
+	m=read();
+	memset(num,0,sizeof(num));
+	for(i=0;i<p;i++)
+	{
+		a=read();b=read();
+		tu[a][num[a]++]=b;
+		tu[b][num[b]++]=a;
+	}
+	node t,t2;
+	t.id=c;
+	t.step=1;
+	queue[tail++]=t;
+	w(c,1);
+	while(head<tail)
+	{
+		t=queue[head++];
+		for(i=0;i<num[t.id];i++)
+			if(!r(tu[t.id][i]))
+			{
+				queue[tail].id=tu[t.id][i];
+				queue[tail].step=t.step+1;
+				w(queue[tail++].id,1);
+			}
+	}
+	printf("%lld\n",queue[tail-1].step+m);
+	return 0;
+}