BulidtreePOandIO.cpp

#include<iostream>
using namespace std;

struct Node{

    int data;
    struct Node *left;
    struct Node *right;

    Node(int val){
        data = val;
        left = NULL;
        right = NULL;
    }
};

int search(int inorder[], int start, int end, int curr){
    for (int i = start; i <+ end; i++){
        if (inorder[i] == curr){
            return i;
        }
    }
    return -1;
}

Node* buildTree(int preorder[], int inorder[], int  start, int end){
    static int idx = 0;

    if(start > end){
        return NULL;
    }

    int curr = preorder[idx];
    idx++;
    Node*node = new Node(curr);

    if(start == end){
        return node;
    }

    int pos = search(inorder,start,end, curr);
    node->left = buildTree(preorder, inorder, start, pos-1);
    node->right = buildTree(preorder, inorder, pos+1, end);

    return node;

}

void inorderPrint(Node*root){
    if(root==NULL){
        return;
    }
    inorderPrint(root->left);
    cout<<root->data<<" ";
    inorderPrint(root->right);
}

int main (){
    int preorder[] = {1,2,4,3,5};
    int inorder[] = {4,2,1,5,3};

   Node*root = buildTree(preorder, inorder, 0, 4);
   inorderPrint(root);

    return 0;
}