void preorder_call(struct node *root, int *arr, int *index)
{
if (root == NULL)
return;
arr[*index] = root->data; (*index)++;
preorder_call(root->left, arr, index);
preorder_call(root->right, arr, index);
}
void preorder_call(node * root, int * arr, int * ptr){
/*
1. First visit data
2. Next Left subtree
3.Next Right subtree
*/
if (root == NULL)
return;
arr[*ptr] = root->data;
(*ptr)++;//must increament here only to retain value in next function call
preorder_call(root->left, arr, ptr);
preorder_call(root->right, arr, ptr);
}
void preorder(struct node *root, int *arr){
if (root == NULL || arr == NULL){
return;
}
int ptr = 0;
preorder_call(root, arr, &ptr);
}
void preorder(struct node *root, int *arr)
{
if (root == NULL || arr == NULL)
return;
int index = 0;
preorder_call(root, arr, &index);
}
