Three kinds of non-recursive traversal methods for binary tree

1. First Order traversal

1 voidpreordertraversal (bintree BT)2 {3 Bintree T;4Std::stack<bintree>Btstack;5T =BT;6      while(T | |!btstack.empty ())7     {8          while(T)9         {Ten Btstack.push (T); Oneprintf"%c", t->Data); AT = t->Left ; -         } -T =btstack.top (); the Btstack.pop (); -T = t->Right ; -  -     } +}

2. Middle Sequence traversal

1 voidinordertraversal (bintree BT)2 {3 Bintree T;4Std::stack<bintree>Btstack;5T =BT;6      while(T | |!btstack.empty ())7     {8          while(T)9         {Ten Btstack.push (T); OneT = t->Left ; A         } -T =btstack.top (); - Btstack.pop (); theprintf"%c", t->Data); -T = t->Right ; -  -     } +}

3. Post-Traversal (heavy difficulty)

Add a data field that represents the number of accesses in the structure node of the tree, visit:

1 typedef Position Bintree;    // two fork Tree type 2 struct tnode {3     ElementType Data;    // node Data 4     int visit; 5     Bintree left;        // point to left dial hand tree 6     Bintree right;        // point to the right sub-tree 7 };

traversing the Code program:

1 voidpostordertraversal (bintree BT)2 {3Bintree T =BT;4Std::stack<bintree>Btstack;5      while(T | |!btstack.empty ())6     {7          while(T)8         {9t->visit++;Ten Btstack.push (T); OneT = t->Left ; A         } -         if(!btstack.empty ()) -         { theT = Btstack.top ();//second or third visit to the node -          -             if(T->visit = =2)//when visit = = 2 o'clock, the node has been accessed 3 times, so it can be output -             { +printf"%c", t->Data); - Btstack.pop (); +T =NULL; A             } at             Else -             { -t->visit++;//Second Visit -T = t->right;//will be entering the third visit -             } -         } in     } -}

Three kinds of non-recursive traversal methods for binary tree