题目链接1 题目链接2 题目大意 给出一个括号序列,添加最少的括号使序列正确 解题思路 先将问题简单化,从求序列退化为求最小添加括号数的问题 用区间dp n³解决 f[l][r]表示使第l个到r个区间正确的最小添加数 1 :当l = r时, f[l][r] = f[l+1][r-1] 2 :  在l到j中,枚举中间点k,则f[l][r] = min (f[l][r], f[l][k] + f[k+1][r]) 求出了最小添加括号数后,再来思考完整的问题 用递归解决输出方案 假设有一个 从 l 到…

sort3解题报告 —— icedream61 博客园(转载请注明出处)------------------------------------------------------------------------------------------------------------------------------------------------[题目] 给你N,而后给出N个数,每个数都是1~3中的一个.请问,要把这个数列升序排好,最少需要进行几次两两交换?[数据范围] 1<=N<…

1.题目描述: 1175. Strange Sequence Time limit: 1.0 secondMemory limit: 2 MB You have been asked to discover some important properties of one strange sequences set. Each sequence of the parameterized set is given by a recurrent formula: Xn+1 = F(Xn-1, Xn)…

A Ducci sequence is a sequence of n-tuples of integers. Given an n-tuple of integers (a1, a2, ... , an), the next n-tuple in the sequence is formed by taking the absolute differences of neighboring integers: ( a1, a2, ... , an)  (| a1 - a2|,| a2 - a3…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 日期 题目地址:https://leetcode.com/problems/split-array-into-fibonacci-sequence/description/ 题目描述 Given a string S of digits, such as S = "123456579", we can split it into a Fib…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 日期 题目地址:https://leetcode.com/problems/permutation-sequence/description/ 题目描述 The set [1,2,3,...,n] contains a total of n! unique permutations. By listing and labeling all of th…

Permutation Sequence https://oj.leetcode.com/problems/permutation-sequence/ The set [1,2,3,…,n] contains a total of n! unique permutations. By listing and labeling all of the permutations in order, We get the following sequence (ie, for n = 3): "123&…

题目 题目描述 给N个整数,每个整数只能是1,2,或3.现在需要对这个整数序列进行从小到大排序,问最少需要进行几次交换.N(1 <= N <= 1000) 样例输入 9 2 2 1 3 3 3 2 3 1 样例输出 4 解题思路 这个题目我没有做出来,想到一个思路,提交之后返回一个wa.后来看了一下题解,才知道自己错在什么地方.现在来回顾一下. 错误思路 我首先统计了1,2,3的个数,记为cnt1,cnt2,cnt3.然后统计在前cnt1个位置有多少个数字不是等于1的,统计在中间cnt2个位置…

Longest Consecutive Sequence Given an unsorted array of integers, find the length of the longest consecutive elements sequence. For example,Given [100, 4, 200, 1, 3, 2],The longest consecutive elements sequence is [1, 2, 3, 4]. Return its length: 4.…

BZOJ 1367 [Baltic2004]sequence Description 给定一个序列\(t_1,t_2,\dots,t_N\),求一个递增序列\(z_1<z_2<\dots<z_N\),使得\(R=|t_1-z_1|+|t_2-z_2|+\dots+|t_N-z_N|\)的值最小,本题中,我们只需求出这个最小的\(R\)值 Input 第\(1\)行为\(N(1\le N\le10^6)\) 第\(2\)行到第\(N+1\)行,每行一个整数.第\(K+1\)行为\(t_k(…