团体程序设计天梯赛 L2-006. 树的遍历 L2-011. 玩转二叉树

L2-006. 树的遍历

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdbool.h>

 struct node
 {
     long left,right;
 }tree[];

 long a[],b[];

 void work(long l,long r,long p,long q,long fa,long cond)
 {
     long root=a[r],pos;
     for (pos=p;pos<=q;pos++)
         if (b[pos]==root)
             break;
     if (cond==)
         tree[fa].left=root;
     else
         tree[fa].right=root;
     if (p<=pos-)
         work(l,l+pos--p,p,pos-,root,);
     if (pos+<=q)
         work(l+pos-p,r-,pos+,q,root,);
 }

 int main()
 {
     long i,head,tail,n;
     long q[];
     scanf("%ld",&n);
     for (i=;i<=n;i++)
     {
         scanf("%ld",&a[i]);
         tree[a[i]].left=;
         tree[a[i]].right=;
     }
     for (i=;i<=n;i++)
         scanf("%ld",&b[i]);
     work(,n,,n,,);

     head=;
     tail=;
     q[]=a[n];
     while (head<tail)
     {
         head++;
         printf("%ld",q[head]);
         if (tree[q[head]].left!=)
         {
             tail++;
             q[tail]=tree[q[head]].left;
         }
         if (tree[q[head]].right!=)
         {
             tail++;
             q[tail]=tree[q[head]].right;
         }
         if (head!=tail)
             printf(" ");
     }
     return ;
 }

L2-011. 玩转二叉树

 #include <stdio.h>
 #include <stdlib.h>

 struct node
 {
     long left,right;
 }tree[];

 long a[],b[],q[];

 void work(long x,long y,long p,long q,long father,long cond)
 {
     long pos,count;
     if (father!=)
     {
         if (cond==)
             tree[father].left=b[p];
         else
             tree[father].right=b[p];
     }
     for (pos=x;pos<=y;pos++)
         if (a[pos]==b[p])
             break;
     count=pos-x;
     if (count>)
         work(x,pos-,p+,p+count,b[p],);
     if (y-pos>)
         work(pos+,y,p+count+,q,b[p],);
 }

 void change(long d)
 {
     if (tree[d].left== && tree[d].right==)
         return ;
     long temp;
     temp=tree[d].left;
     tree[d].left=tree[d].right;
     tree[d].right=temp;
     change(tree[d].left);
     change(tree[d].right);
 }

 int main()
 {
     long n,i,head,tail;
     scanf("%ld",&n);
     for (i=;i<=n;i++)
         scanf("%ld",&a[i]); //mid
     for (i=;i<=n;i++)
         scanf("%ld",&b[i]);    //pre
     for (i=;i<=n;i++)
     {
         tree[i].left=;
         tree[i].right=;
     }
     work(,n,,n,,);
     change(b[]);

     head=; tail=;
     q[]=b[];
     while (head<tail)
     {
         head++;
         printf("%ld",q[head]);
         if (tree[q[head]].left!=)
         {
             tail++;
             q[tail]=tree[q[head]].left;
         }
         if (tree[q[head]].right!=)
         {
             tail++;
             q[tail]=tree[q[head]].right;
         }
         if (head!=tail)
             printf(" "); //output不能多余的空格
     }
     return ;
 }