Submission #19422169

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Source Code Expand

#include <cstdio>
#define reg register
#define min(_a,_b) (_a<_b?_a:_b)
const int N=100002;
int fir[N],d[N],fa[N],nex[N<<1],to[N<<1],s1[N],s2[N],st[N],tot,tl,sum,top,ed;
bool vis[N];
int R()
{
	reg int x=0; reg bool f=0; reg char ch=getchar();
	for(;ch<48||ch>57;ch=getchar()) f|=ch=='-';
	for(;ch>=48&&ch<=57;ch=getchar()) x=x*10+ch-48;
	return f?-x:x;
}
void add(reg int u,reg int v)
{
	nex[++tot]=fir[u],fir[u]=tot,to[tot]=v,++d[u]; 
}
void dfs(reg int u,reg int dis)
{
	if(dis>sum) sum=dis,ed=u;
	for(reg int i=fir[u];i;i=nex[i])
		if(to[i]!=fa[u]) fa[to[i]]=u,dfs(to[i],dis+1);
}
int main()
{
	reg int n=R(),i,j,u,v,now,cmp=0;
	for(i=1;i<n;++i) {
		u=R(),v=R();
		add(u,v),add(v,u);
	}
	fa[1]=0,dfs(1,0);
	u=ed;
	sum=fa[u]=0,dfs(u,0);
	v=ed;
	for(i=v;i!=u;i=fa[i]) st[++top]=i,vis[i]=1;
	st[++top]=u,vis[u]=1,tot=tl=0;
	for(i=1;i<=top;++i) {
		now=++tot;
		for(j=fir[st[i]];j;j=nex[j]) if(!vis[to[j]]) {
			if(d[to[j]]>1) return puts("-1"),0;
			s1[++tl]=++tot;
		}
		s1[++tl]=now;
	}
	tot=tl=0;
	for(i=top;i;--i) {
		now=++tot;
		for(j=fir[st[i]];j;j=nex[j])
			if(!vis[to[j]]) s2[++tl]=++tot; 
		s2[++tl]=now;
	}
	for(i=1;i<=tl;++i)
		if(s1[i]!=s2[i]) {
			cmp=s1[i]<s2[i];
			break;
		}
	if(cmp) for(i=1;i<=n;++i) printf("%d ",s1[i]);
	else for(i=1;i<=n;++i) printf("%d ",s2[i]);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int R()’:
./Main.cpp:9:10: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wregister]
    9 |  reg int x=0; reg bool f=0; reg char ch=getchar();
      |          ^
./Main.cpp:9:24: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wregister]
    9 |  reg int x=0; reg bool f=0; reg char ch=getchar();
      |                        ^
./Main.cpp:9:38: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wregister]
    9 |  reg int x=0; reg bool f=0; reg char ch=getchar();
      |                                      ^~
./Main.cpp: At global scope:
./Main.cpp:14:18: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wregister]
   14 | void add(reg int u,reg int v)
      |                  ^
./Main.cpp:14:28: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wregister]
   14 | void add(reg int u,reg int v)
      |                            ^
./Main.cpp:18:18: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wregister]
   18 | void dfs(reg int u,reg int dis)
      |                  ^
./Main.cpp:18:28: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wregister]
   18 | void dfs(reg int u,reg int dis)
      |                            ^~~
./Main.cpp: In function ‘void dfs(int, int)’:
./Main.cpp:21:14: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wregister]
   21 |  for(reg int i=fir[u];i;i=nex[i])
      |              ^
./Main.cpp: In function ‘int main()’:
./Main.cpp:26:10: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wregister]
   26 |  reg int n=R(),i,j,u,v,now,cmp=0;
      |          ^
./Main.cpp:26:16: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wregister]
   26 |  reg int n=R(),i,j,u,v,now,cmp=0;
      |                ^
./Main.cpp:26:18: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wr...

Judge Result