cf29d 深搜，dfs序

#include
using namespace std;
#define maxn 500
struct Edge{int to,nxt;}edge[maxn<<1];
int n,head[maxn],tot,a[maxn],k;
vector<int>v;
void init(){
    memset(head,-1,sizeof head);
    k=tot=0;
}
void addedge(int u,int v){
    edge[tot].to=v;edge[tot].nxt=head[u];head[u]=tot++;
}
bool dfs(int root,int u,int pre)
{
    if(root==u)return 1;
    for(int i=head[u]; i>=0; i=edge[i].nxt)
    {
        int vv=edge[i].to;
        if(vv==pre)continue;
        if(dfs(root,vv,u))
        {
            v.push_back(u);
            return 1;
        }
    }
    return 0;
}
int main(){
    init();
    
    cin>>n;
    for(int i=1;i){
        int u,v;cin>>u>>v;
        addedge(u,v);
        addedge(v,u);
    }
    int u;
    while(cin>>u)a[++k]=u;
    v.push_back(1);
    dfs(1,a[1],0);
    int last=a[1];

    for(int i=2;i<=k;i++)
        dfs(last,a[i],0),last=a[i];
    dfs(a[k],1,0);
    if(v.size()!=2*n-1)puts("-1");
    else {
        for(int i=0;i)
            printf("%d ",v[i]);
        printf("\n");
    }
}

 

转载于:https://www.cnblogs.com/zsben991126/p/10333330.html