免费的开发网站建设,网络培训心得体会教师,产品review网站怎么做,建设工程168网手机版下载目录 1 单值二叉树
2 相同的树
3 另一颗树的子树
4 二叉树的前序遍历
5 二叉树的最大深度
6 对称二叉树
7 二叉树遍历 1 单值二叉树
965. 单值二叉树 - 力扣#xff08;LeetCode#xff09; bool isUnivalTree(struct TreeNode* root) {if (root NULL){return true;}…目录 1 单值二叉树
2 相同的树
3 另一颗树的子树
4 二叉树的前序遍历
5 二叉树的最大深度
6 对称二叉树
7 二叉树遍历 1 单值二叉树
965. 单值二叉树 - 力扣LeetCode bool isUnivalTree(struct TreeNode* root) {if (root NULL){return true;}if (root-left root-val ! root-left-val){return false;}if (root-right root-val ! root-right-val){return false;}return isUnivalTree(root-left) isUnivalTree(root-right);}2 相同的树
100. 相同的树 - 力扣LeetCode /*
* Definition for a binary tree node.
* struct TreeNode {*int val;*struct TreeNode* left;*struct TreeNode* right;*
};
*/
bool isSameTree(struct TreeNode* p, struct TreeNode* q) {if (p NULL q NULL){return true;}if (p NULL || q NULL)//这里是说只有一个为空 另一个不为空 两个都为空的情况已经被上个判断语句排除了{return false;}if (p-val ! q-val){return false;}return isSameTree(p-left, q-left) isSameTree(p-right, q-right);}3 另一颗树的子树
572. 另一棵树的子树 - 力扣LeetCode /*** Definition for a binary tree node.* struct TreeNode {* int val;* struct TreeNode *left;* struct TreeNode *right;* };*/bool isSametree(struct TreeNode* p, struct TreeNode* q)
{if (p NULL q NULL){return true;}if (p NULL || q NULL){return false;}if (p-val ! q-val){return false;}return isSametree(p-left, q-left) isSametree(p-right, q-right);
}
bool isSubtree(struct TreeNode* root, struct TreeNode* subRoot) {if (root NULL){return false;}if (root-val subRoot-val){if (isSametree(root, subRoot)){return true;}}return isSubtree(root-left, subRoot) || isSubtree(root-right, subRoot);}
4 二叉树的前序遍历
144. 二叉树的前序遍历 - 力扣LeetCode
/*** Definition for a binary tree node.* struct TreeNode {* int val;* struct TreeNode *left;* struct TreeNode *right;* };*//*** Note: The returned array must be malloced, assume caller calls free().*/int TreeSize(struct TreeNode* root)
{return root NULL ? 0 : TreeSize(root-left) TreeSize(root-right) 1;
}void PrevOrder(struct TreeNode* root, int* a, int* i)//这里的i 之所以传指针是因为递归的时候要保存上一次i的值
{if (root NULL){return;}a[*i] root-val;(*i);PrevOrder(root-left, a, i);PrevOrder(root-right, a, i);
}
int* preorderTraversal(struct TreeNode* root, int* returnSize) {int n TreeSize(root);int* a (int*)malloc(sizeof(int) * n);int j 0;PrevOrder(root, a, j);//这里j取地址*returnSize n;return a;
}
5 二叉树的最大深度
力扣LeetCode官网 - 全球极客挚爱的技术成长平台
/*** Definition for a binary tree node.* struct TreeNode {* int val;* struct TreeNode *left;* struct TreeNode *right;* };*/int maxDepth(struct TreeNode* root) {if (root NULL){return 0;}int ret1 maxDepth(root-left);int ret2 maxDepth(root-right);return (fmax(ret1, ret2) 1);}
6 对称二叉树
101. 对称二叉树 - 力扣LeetCode
/*** Definition for a binary tree node.* struct TreeNode {* int val;* struct TreeNode *left;* struct TreeNode *right;* };*/bool isSameTree(struct TreeNode* p, struct TreeNode* q)
{if (p NULL q NULL){return true;}if (p NULL || q NULL){return false;}if (p-val ! q-val){return false;}return isSameTree(p-left, q-right) isSameTree(p-right, q-left);
}
bool isSymmetric(struct TreeNode* root) {if (root NULL){return NULL;}return isSameTree(root-left, root-right);
}
7 二叉树遍历
二叉树遍历_牛客题霸_牛客网 #include stdio.h
#includestdlib.h
typedef struct BianryTreeNode
{struct BianryTreeNode* left;struct BianryTreeNode* right;char val;
}BTNode;BTNode* CreatTree(char* a, int* i)//前序遍历
{if (a[*i] #){(*i);return NULL;}BTNode* root (BTNode*)malloc(sizeof(BTNode));root-val a[*i];(*i);root-left CreatTree(a, i);root-right CreatTree(a, i);return root;
}void PrintInOrder(BTNode* root)//中序遍历
{if (root NULL){return;}PrintInOrder(root-left);printf(%c , root-val);PrintInOrder(root-right);
}
int main() {char arr[100];scanf(%s, arr);int i 0;BTNode* root CreatTree(arr, i);PrintInOrder(root);return 0;
}
本节对二叉树的一些常规OJ题目进行了代码实现和讲解, 虽然图解很少, 但是大家根据代码和注释也可以很好理解,也可以自己画一画递归展开图.本节对二叉树链式结构的基础要求很高, 大家如果基础不好,可以先看看我之前的博客.
继续加油!
