题意 给定一个整数N,请你求出有多少字符集为1到K之间整数的字符串,使得该字符串可以由一个长度为N的回文串循环移位后得到.所谓循环移位,就是把字符串的某个前缀(可以为空)移到字符串末尾,如"1221"循环移位可以得到"1221"."2211"."2112"."1122"四个字符串.结果对$10^9+7$取模 题解 考试时花了差不多一个小时推了一个$O(n)$的式子,还妄想着能优化到$O(sqrt(n))$.…

Description 然而,由于小C沉迷于制作游戏,他完全忘记了自己作为国家集训队的一员,还有156道作业题等他完成.还有一天作业就要截止了,而他一题还没有做.于是他赶紧挑了一道看起来最简单的题: "给定一个整数N,请你求出有多少字符集为1到K之间整数的字符串,使得该字符串可以由一个长度为N的回文串循环移位后得到.所谓循环移位,就是把字符串的某个前缀(可以为空)移到字符串末尾,如"1221"循环移位可以得到"1221"."2211".…

Problem Statement Takahashi and Aoki are going to together construct a sequence of integers. First, Takahashi will provide a sequence of integers a, satisfying all of the following conditions: The length of a is N. Each element in a is an integer bet…

题意 给你一个正整数 \(n\),求有多少字符集为 \(1\) 到 \(k\) 之间整数的字符串,使得该字符串可以由一个长度为 \(n\) 的回文串循环移位得到. ARC原题 \(100\%\) 的数据是 \(n,k\le 10^9\) SDOI改编后,\(30\%\) 的数据是 \(n,k\le 10^{10}\),\(60\%\) 的数据是 \(n,k\le 10^{14}\),\(100\%\) 的数据是 \(n,k\le 10^{18}\)-- 题解 \(n,k\le 10^{10}\)…

(长度为$n$的序列$a_{i}$,下标范围为$[0,n)$,且用字符串的方式即$a_{[l,r]}$来表示子区间) 定义一个长为$n$的序列$a_{i}$的周期为的$l$满足$l|n$且$\forall l\le i<n,a_{i}=a_{i+l}$(这里不同于普通周期的定义,普通周期定义是没有$l|n$这个要求的),最小正周期即为其中最小的正整数$l$ 先考虑枚举一开始回文的$a_{i}$,再将其轮换来构造出所有$a_{i}$,可以证明具有这样两个性质: 1.若一个序列$a_{i}$是回文的…

一句话题解 因为上篇AGC的写的有点长……估计这篇也短不了所以放个一句话题解方便查阅啥的吧QwQ 具体的题意代码题解还是往下翻…… ARC 058 D:简单容斥计数. E:用二进制表示放的数字,然后状压$DP$. F:$biset$优化$DP$预处理,乱搞贪心. ARC 059 D:傻题,存在长的合法子串就一定会存在短的. E:前缀和优化$DP$. F:每个长度为$len$的串出现的概率是相同的,求到长度为$len$的方案数然后除$2^{len}$. ARC 060 D:对$b$分大于根号和小于…

ARC064 C - Boxes and Candies 先把每个盒子都消到x 然后从前往后推,要求第二个的上界是x-前一个 因为我们要求靠后的那个尽量小,会对后面的修改影响尽量小 #include <bits/stdc++.h> #define fi first #define se second #define pii pair<int,int> #define mp make_pair #define pb push_back #define space putchar('…

Follow up for "Find Minimum in Rotated Sorted Array":What if duplicates are allowed? Would this affect the run-time complexity? How and why? Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might be…

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). Find the minimum element. You may assume no duplicate exists in the array. 这道寻找旋转有序数组的最小值肯定不能通过直接遍历整个数组来寻找,这个方法过于简单粗暴,这样的话,旋不…

Follow up for "Search in Rotated Sorted Array":What if duplicates are allowed? Would this affect the run-time complexity? How and why? Write a function to determine if a given target is in the array. 这道是之前那道Search in Rotated Sorted Array 在旋转有序数组…

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). You are given a target value to search. If found in the array return its index, otherwise return -1. You may assume no duplic…

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). You are given a target value to search. If found in the array return its index, otherwise return -1. You may assume no duplic…

UVA - 11584 Partitioning by Palindromes We say a sequence of char- acters is a palindrome if it is the same written forwards and backwards. For example, ‘racecar’ is a palindrome, but ‘fastcar’ is not. A partition of a sequence of characters is a lis…

题目概述: Suppose a sorted array is rotated at some pivot unknown to you beforehand.(i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).Find the minimum element.You may assume no duplicate exists in the array. 解题思路: 在一个有顺序的数组中查找个最小值,很容易想到的就是二分法,的确,这里用的就是二分,…

1. 画图, 直观. 2. 讨论数组为空或者个数为零. 3. 讨论首尾, 若为翻转过的则进行查找直到最后两个数进行比较, 取小者. public class Solution { /** * @param num: a rotated sorted array * @return: the minimum number in the array */ public int findMin(int[] num) { // write your code here if(num == null ||…

Follow up for "Search in Rotated Sorted Array": What if duplicates are allowed? Would this affect the run-time complexity? How and why? Write a function to determine if a given target is in the array. 解决方法就是对于A[mid]==A[left]和A[mid]==A[right]单独处理…

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). You are given a target value to search. If found in the array return its index, otherwise return -1. You may assume no duplic…

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). Find the minimum element. You may assume no duplicate exists in the array. 在任何一个sublist中,如果头元素大于尾元素,那么这个minimum一定在这个sublist中间…

Palindromes Time Limit:3000MS     Memory Limit:0KB     64bit                                                                                         IO Format:%lld & %llu Description A regular palindrome is a string of numbers or letters that is the…

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). Find the minimum element. You may assume no duplicate exists in the array. 分析: 这道题给出了一个有序数组,找出数组中最小的元素,其实就是找出第一个小于最后一个元素出现的位置…

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). You are given a target value to search. If found in the array return its index, otherwise return -1. You may assume no duplic…

Search in Rotated Sorted Array II Follow up for "Search in Rotated Sorted Array":What if duplicates are allowed? Would this affect the run-time complexity? How and why? Write a function to determine if a given target is in the array.   与I类似,只是在二…

Search in Rotated Sorted Array Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). You are given a target value to search. If found in the array return its index, otherwise retu…

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). You are given a target value to search. If found in the array return its index, otherwise return -1. You may assume no duplic…

Follow up for "Search in Rotated Sorted Array":What if duplicates are allowed? Would this affect the run-time complexity? How and why? Write a function to determine if a given target is in the array. 我的思路: 太混乱了 不提了.注意关键区分依据 排好序的一定是从小到大的 看大神的吧: b…

1. 无重复 Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). Find the minimum element. You may assume no duplicate exists in the array. 思路:这个是找最小,和找指定数字其实差不多的.画个示意图吧 二分查找,关键是扔掉不包含…

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). Find the minimum element. You may assume no duplicate exists in the array. 二分查找就行了. class Solution { public: int findMin(vect…

Search in Rotated Sorted Array Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). You are given a target value to search. If found in the array return its index, otherwise retu…

原题链接 直接贴代码,这道题是 search in rotated sorted array leetcode 的前面部分! class Solution { public: int findMin(vector<int>& nums) { if (nums.empty()) ; , nums.size()-);//好神奇,第二个参数无论减或者不减1,都不影响该题的结果 ) ; return nums[res]; } int find(vector<int>& nu…

原题链接,点我 该题解题参考博客 和Search in Rotated Sorted Array唯一的区别是这道题目中元素会有重复的情况出现.不过正是因为这个条件的出现,出现了比较复杂的case,甚至影响到了算法的时间复杂度.原来我们是依靠中间和边缘元素的大小关系,来判断哪一半是不受rotate影响,仍然有序的.而现在因为重复的出现,如果我们遇到中间和边缘相等的情况,我们就丢失了哪边有序的信息,因为哪边都有可能是有序的结果.假设原数组是{1,2,3,3,3,3,3},那么旋转之后有可能是{3,3…