IN - ORDER TRAVERSAL IN BINARY SEARCH TREE

Here, is code of  in - order traversal in binary search tree with using recursive method.
All you have to do is follow these steps:

1) Create an empty stack S.
2) Initialize current node as root

   Here starts our loop,
3) Push the current node to S and set current = current->left until current is NULL

4) If current is NULL and stack is not empty then 
     a) Pop the top item from stack.
     b) Print the popped item, set current = current->right 
     c) Go to step 3.
5) If current is NULL and stack is empty then we are done.

#include<stdio.h>
#include<iostream>

using namespace std;

struct node
{
    int val;
    node *left;
    node *right;
}*root;

void make_tree(node **temp,int i)
{
    if((*temp) == NULL)
    {
        (*temp) = new node;
        (*temp)->val = i;
        (*temp)->right = (*temp)->left = NULL;
    }

    else if((*temp)->val > i)
    {
        make_tree(&(*temp)->left,i);
    }

    else
    {
        make_tree(&(*temp)->right,i);
    }
}

void in_order(node *temp)
{
    node *stk[500]; int index = 0;

 stk[index] = temp;
 temp = temp->left;

    while(temp || index != -1)
    {
        if(temp != NULL)
        {
            stk[++index] = temp;
            temp = temp->left;
        }

        else
        {
            temp = stk[index--];
            cout<<temp->val<<"\t";
            temp = temp->right;
        }
    }

    cout<<"\n";
}

int main()
{
    int n,i;

    cin>>n;

    while(n--)
    {
        cin>>i;

        make_tree(&root,i);
    }

    cout<<"In - Order Traversal     :   ";

    in_order(root);

    return 0;
}