The count-and-say sequence is the sequence of integers beginning as follows: 1, 11, 21, 1211, 111221, ... 1 is read off as "one 1" or 11. 11 is read off as "two 1s" or 21. 21 is read off as "one 2, then one 1" or 1211. Given…

The count-and-say sequence is the sequence of integers beginning as follows:1, 11, 21, 1211, 111221, ... 1 is read off as "one 1" or 11.11 is read off as "two 1s" or 21.21 is read off as "one 2, then one 1" or 1211. Given an…

The count-and-say sequence is the sequence of integers with the first five terms as following: 1. 1 2. 11 3. 21 4. 1211 5. 111221 1 is read off as "one 1" or 11.11 is read off as "two 1s" or 21.21 is read off as "one 2, then one 1…

Count and Say 计数和发言 思路:首先要理解题意,可以发现后者是在前者的基础之上进行的操作,所以我们拿之前的结果作为现在函数的参数循环n-1次即可,接下来就是统计字符串中相应字符的个数,需要注意的是最后一个字符别忘了处理. class Solution(object): def countAndSay(self, n): """ :type n: int :rtype: str """ if n < 2: return '1'…

466. 链表节点计数 计算链表中有多少个节点.   样例 给出 1->3->5, 返回 3. /** * Definition of ListNode * class ListNode { * public: * int val; * ListNode *next; * ListNode(int val) { * this->val = val; * this->next = NULL; * } * } */ class Solution { public: /* * @para…

The count-and-say sequence is the sequence of integers beginning as follows:1, 11, 21, 1211, 111221, ... 1is read off as"one 1"or11.11is read off as"two 1s"or21.21is read off as"one 2, thenone 1"or1211. Given an integer n, ge…

D. Count the Arrays 也是一个计数题. 题目大意: 要求构造一个满足题意的数列. \(n\) 代表数列的长度 数列元素的范围 \([1,m]\) 数列必须有且仅有一对相同的数 存在一个位置 \(i\),使得小于 \(i\) 这个位置的是严格递增的,大于这个位置则是严格递减的. 这个题目也很容易把自己绕晕,所以我们要想开点... 不要去太细节的考虑哪一个位置放什么之类的,而是考虑如何构造满足条件的序列. 因为序列长度是 \(n\),范围是 \(m\),而且又必须有一对相同的数.…

Given a binary tree, count the number of uni-value subtrees. A Uni-value subtree means all nodes of the subtree have the same value. For example:Given binary tree, 5 / \ 1 5 / \ \ 5 5 5 return 4. 这道题让我们求相同值子树的个数,就是所有节点值都相同的子树的个数,之前有道求最大BST子树的题Largest…

Give you an integer array (index from 0 to n-1, where n is the size of this array, value from 0 to 10000) and an query list. For each query, give you an integer, return the number of element in the array that are smaller than the given integer. Have…

Warning: input could be > 10000... Solution by segment tree: struct Node { Node(), left(nullptr), right(nullptr) {}; int start; int end; int cnt; // Node *left; Node *right; }; class Solution { Node *pRoot; void update(int v) { Node *p = pRoot; while…