#include <iostream>
#include <stack>using namespace std;typedef struct BinaryTree
{struct BinaryTree *left,*right;int data;
}BinaryTree;int flag = 0;
void initTree(BinaryTree **p,BinaryTree **a,BinaryTree **b);
BinaryTree *GetLowestParent(BinaryTree *root,BinaryTree *X,BinaryTree *Y);int main(void)
{BinaryTree *root,*a,*b;initTree(&root,&a,&b);BinaryTree *parent = GetLowestParent(root,a,b);if(parent && flag==2)cout << "最低公共父结点的值为:" << parent->data << endl;elsecout << "没有最低公共父结点!" << endl;a = new BinaryTree;flag = 0;parent = GetLowestParent(root,a,b);if(parent && flag==2)cout << "最低公共父结点的值为:" << parent->data << endl;elsecout << "没有最低公共父结点!" << endl;return 0;
}
//      10
//     / \
//    5   12
//   / \
//  4   7
void initTree(BinaryTree **p,BinaryTree **a,BinaryTree **b)
{*p = new BinaryTree;(*p)->data = 10;BinaryTree *tmpNode = new BinaryTree;tmpNode->data = 5;(*p)->left = tmpNode;tmpNode = new BinaryTree;*b = tmpNode;tmpNode->data = 12;(*p)->right = tmpNode;tmpNode->left = NULL;tmpNode->right = NULL;BinaryTree *currentNode = (*p)->left;tmpNode = new BinaryTree;*a = tmpNode;tmpNode->data = 4;currentNode->left = tmpNode;tmpNode->left = NULL;tmpNode->right = NULL;tmpNode = new BinaryTree;tmpNode->data = 7;currentNode->right = tmpNode;tmpNode->left = NULL;tmpNode->right = NULL;cout << "二叉树为：" <<endl;cout << "     " << 10<<endl;cout << "    " <<"/" << "  "<< "\\" <<endl;cout << "   " << 5 << "    " << 12 << endl;cout << " " <<"/" << "  "<< "\\" <<endl;cout << 4 << "    " << 7 << endl;
}
BinaryTree *GetLowestParent(BinaryTree *root,BinaryTree *X,BinaryTree *Y)
{if(root == NULL)return NULL;if(X==root || Y==root){flag++;return root;}BinaryTree *left = GetLowestParent(root->left,X,Y);BinaryTree *right = GetLowestParent(root->right,X,Y);if(left==NULL && right==NULL)return NULL;else if(left==NULL)return right;else if(right==NULL)return left;elsereturn root;
}