algo_046.md (526B)
1 # algo_046 2 3 ### Problem Statement 4 5 > Write a non-recursive algorithm for preorder traversal of a binary tree. 6 7 ## Algorithm 8 ``` 9 procedure preorder(T) 10 begin 11 ptr ← T; 12 flag ← 1; 13 while (flag = 1) do 14 while (ptr ≠ NULL) do 15 write(INFO(ptr)); 16 push(stack, ptr); 17 ptr ← LC(ptr); 18 endwhile 19 if (!isEmpty(stack)) then 20 ptr ← pop(stack); 21 ptr ← RC(ptr); 22 else 23 flag ← 0; 24 endif 25 endwhile 26 end procedure 27 ```