데이터 구조와 알고리즘 - 두 갈래 정렬 트리의 최대 최소값 검색

BinaryTreeNode* Find_Min(BinaryTreeNode* BST){
    if(!BST)
        return NULL;
    else if( !BST->left )
        return BST;
    else
        return Find_Min( BST->left );
}

BinaryTreeNode* Find_Min_Recurrence(BinaryTreeNode* BST){
    if(BST)
        while(BST->left)
            BST = BST->left;
    return BST;
}

BinaryTreeNode* Find_Max(BinaryTreeNode* BST){
    if(!BST)
        return NULL;
    else if( !BST->right )
        return BST;
    else
        return Find_Max( BST->right );
}

BinaryTreeNode* Find_Max_Recurrence(BinaryTreeNode* BST){
    if(BST)
        while(BST->right)
            BST = BST->right;
    return BST;
}

#include 

using namespace std;

struct BinaryTreeNode {
    int val;
    BinaryTreeNode *left;
    BinaryTreeNode *right;
    BinaryTreeNode(int x) : val(x), left(NULL), right(NULL) {}
};

BinaryTreeNode* Find_Min(BinaryTreeNode* BST){
    if(!BST)
        return NULL;
    else if( !BST->left )
        return BST;
    else
        return Find_Min( BST->left );
}


BinaryTreeNode* Find_Min_Recurrence(BinaryTreeNode* BST){
    if(BST)
        while(BST->left)
            BST = BST->left;
    return BST;
}

BinaryTreeNode* Find_Max(BinaryTreeNode* BST){
    if(!BST)
        return NULL;
    else if( !BST->right )
        return BST;
    else
        return Find_Max( BST->right );
}

BinaryTreeNode* Find_Max_Recurrence(BinaryTreeNode* BST){
    if(BST)
        while(BST->right)
            BST = BST->right;
    return BST;
}

int main(){
    BinaryTreeNode a(8);
    BinaryTreeNode b(3);
    BinaryTreeNode c(10);
    BinaryTreeNode d(1);
    BinaryTreeNode e(6);
    BinaryTreeNode f(15);
    a.left = &b;
    a.right = &c;
    b.left = &d;
    b.right = &e;
    c.right = &f;

    BinaryTreeNode* res = Find_Min(&a);
    if(!res)
        printf("no
");
    else
        printf("%d
",res->val);

    BinaryTreeNode* res1 = Find_Min_Recurrence(&a);
    if(!res1)
        printf("no
");
    else
        printf("%d
",res1->val);

    BinaryTreeNode* res3 = Find_Max(&a);
    if(!res3)
        printf("no
");
    else
        printf("%d
",res3->val);

    BinaryTreeNode* res4 = Find_Max_Recurrence(&a);
    if(!res4)
        printf("no
");
    else
        printf("%d
",res4->val);
    return 0;
}