Create a tree with (pre and inorder)

#1

In this solution, I am using hash map to make it O(n)


for this test case it is giving wrong answer
1
8
4 8 2 5 1 6 3 7
8 4 5 2 6 7 3 1
correct answer is
1 2 4 8 5 3 6 7

#2

approach is correct but you have done 2 mistakes

  1. make root node with c not with inorder[index]
  2. increase i before returning

and correct output for you given input is
Output
8 4 5 2 6 7 3 1
not 1 2 4 8 5 3 6 7

 int c = pre[i];

int index = mp[c];

i++;

node * root = new node(c);

after these changes it is giving correct output

MODIFIED CODE

#3

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