[173] Binary Search Tree Iterator

說真的，我到底在寫什麼啊 Orz

覺得自己卡住老半天的理由完全廢到笑.........

/**

* Definition for a binary tree node.

* struct TreeNode {

* int val;

* struct TreeNode *left;

* struct TreeNode *right;

* };

*/

typedef struct {

int val[100000];

int count;

int curr;

} BSTIterator;

void insert(struct TreeNode* root, int level, BSTIterator* obj)

{

if (root == NULL || obj == NULL)

return;

if (root->left != NULL)

insert(root->left,level+1, obj);

obj->val[(obj->count)++]= root->val;

if (root->right != NULL)

insert(root->right, level+1, obj);

return;

}

BSTIterator* bSTIteratorCreate(struct TreeNode* root) {

if (root == NULL)

return NULL;

BSTIterator* ptr = malloc (sizeof (BSTIterator));

ptr->count = 0;

ptr->curr = 0;

insert(root, 0, ptr);

return ptr;

}

int bSTIteratorNext(BSTIterator* obj) {

if (obj-> count>0)

return obj->val[(obj->curr)++];

return NULL;

}

bool bSTIteratorHasNext(BSTIterator* obj) {

return (obj->curr < obj-> count) ? true : false;

}

void bSTIteratorFree(BSTIterator* obj) {

free(obj);

return;

}

/**

* Your BSTIterator struct will be instantiated and called as such:

* BSTIterator* obj = bSTIteratorCreate(root);

* int param_1 = bSTIteratorNext(obj);

* bool param_2 = bSTIteratorHasNext(obj);

* bSTIteratorFree(obj);

*/