[700] Search in a Binary Search Tree

其實我不知道為什麼我寫的那麼複雜 囧

亡盪惹

struct TreeNode* searchBST(struct TreeNode* root, int val){

if (root==NULL)

return NULL;

struct TreeNode* ptr=root;

if (root->val < val )

ptr = searchBST(root->right,val);

else if (root->val > val )

ptr = searchBST(root->left,val);

else if (root->val == val)

return root;

else

return NULL;

return ptr;

}

其實只要這樣就好了!!!

struct TreeNode* searchBST(struct TreeNode* root, int val){

if (root==NULL)

return NULL;

if (root->val < val )

return searchBST(root->right,val);

if (root->val > val )

return searchBST(root->left,val);

if (root->val == val)

return root;

return NULL;

}

而且重點是，根本不用用遞迴啊啊啊啊啊啊啊（抱頭）我到底在想什麼呢Orz

struct TreeNode* searchBST(struct TreeNode* root, int val){

struct TreeNode* ptr=root;

while (ptr !=NULL)

{

if (ptr->val >val)

ptr = ptr->left;

else if (ptr->val < val)

ptr= ptr->right;

else if (ptr->val ==val)

return ptr;

}

return NULL;

}