传送门 题目大意 给出由1-n组成的序列,每次可将一个区间翻转.问如何从1-n的递增序列变成给出的序列,输出操作次数以及每次操作的区间.最多翻转3次,保证有解,输出任意方案即可. 分析 我们对于每一次翻转只考虑枚举所有可能的点,即我们找出每一段连续区间的两个端点,然后枚举选取这些端点中的哪两个,之后暴力翻转这一段区间即可. 代码 #include<iostream> #include<cstdio> #include<cstring> #include<strin…

[codeforces 339]E. Three Swaps 试题描述 Xenia the horse breeder has n (n > 1) horses that stand in a row. Each horse has its own unique number. Initially, the i-th left horse has number i. That is, the sequence of numbers of horses in a row looks as foll…

Mapping the Swaps Sorting an array can be done by swapping certain pairs of adjacent entries in the array. This is the fundamental technique used in the well-known bubble sort. If we list the identities of the pairs to be swapped, in the sequence the…

题目例如以下: Mapping the Swaps  Sorting an array can be done by swapping certain pairs of adjacent entriesin the array. This is the fundamental technique used in the well-knownbubble sort. If we list the identities of the pairs to be swapped, in thesequen…

E. Three Swaps time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Xenia the horse breeder has n (n > 1) horses that stand in a row. Each horse has its own unique number. Initially, the i-th le…

哥德巴赫猜想: 任一大于2的偶数,都可表示成两个素数之和. 任一大于5的整数都可写成三个质数之和. 贪心取尽可能大的素数..... C. Prime Swaps time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You have an array a[1], a[2], ..., a[n], containing distinc…

Swaps in Permutation You are given a permutation of the numbers 1, 2, ..., n and m pairs of positions (aj, bj). At each step you can choose a pair from the given positions and swap the numbers in that positions. What is the lexicographically maximal…

We have two integer sequences A and B of the same non-zero length. We are allowed to swap elements A[i] and B[i].  Note that both elements are in the same index position in their respective sequences. At the end of some number of swaps, A and B are b…

We have two integer sequences A and B of the same non-zero length. We are allowed to swap elements A[i] and B[i].  Note that both elements are in the same index position in their respective sequences. At the end of some number of swaps, A and B are b…

源代码超时 看了评论区改用了字典序列. #!/bin/python3 import math import os import random import re import sys # Complete the minimumSwaps function below. def minimumSwaps(arr): # n = len(arr) # count = 0 # for i in range(n): # if i > 0: # if i == arr[i-1]: # continue…

版权声明:本文为博主原创文章,未经博主同意不得转载. https://blog.csdn.net/u011328934/article/details/26094917 题目连接:Codefoces 432C Prime Swaps 题目大意:给出一个序列.长度为n,要求用5n以内的交换次数使得序列有序.而且交换的i,j两个位置的数时要满足,j−i+1为素数. 解题思路:a数组为相应的序列,b数组为相应的有序序列,p为相应数的位置.每次从有序序列最小的位置開始,该为必须放b[i]才对.所以p[b…

A permutation p of length n is a sequence of distinct integers p1, p2, ..., pn (1 ≤ pi ≤ n). A permutation is an identity permutation, if for any i the following equation holds pi = i. A swap (i, j) is the operation that swaps elements pi and pj in t…

D. Swaps in Permutation 题目连接: http://www.codeforces.com/contest/691/problem/D Description You are given a permutation of the numbers 1, 2, ..., n and m pairs of positions (aj, bj). At each step you can choose a pair from the given positions and swap…

题意 3602 Counting Swaps 0x30「数学知识」例题 背景 https://ipsc.ksp.sk/2016/real/problems/c.html Just like yesterday (in problem U of the practice session), Bob is busy, so Alice keeps on playing some single-player games and puzzles. In her newest puzzle she has…

We have two integer sequences A and B of the same non-zero length. We are allowed to swap elements A[i] and B[i].  Note that both elements are in the same index position in their respective sequences. At the end of some number of swaps, A and B are b…

Swaps and Inversions Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2315    Accepted Submission(s): 882 Problem Description Long long ago, there was an integer sequence a.Tonyfang think this se…

[CC-CHEFINV]Chef and Swaps 题目大意: 长度为\(n(n\le2\times10^5)\)的数列,\(q(q\le2\times10^5)\)次询问,每次问交换\(A_x\)和\(A_y\)后逆序对个数.询问互相独立. 思路: 一开始先把逆序对求好,然后用主席树计算交换对答案的影响即可. 时间复杂度\(\mathcal O((n+q)\log n)\). 源代码: #include<cstdio> #include<cctype> #include<…

A. Sereja and Swaps time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output As usual, Sereja has array a, its elements are integers: a[1], a[2], ..., a[n]. Let's introduce notation: A swap operatio…

Counting swaps 给你一个1-n的排列,问用最少的交换次数使之变为递增排列的方案数\(mod\ 10^9+7\),1 ≤ n ≤ 10^5. 解 显然最少的交换次数不定,还得需要找到最小交换次数,而考虑到交换为复杂的过程,考虑状态的性质,所以不难想到画出,+为箭头指向方向 _ _ | + | + 2 1 4 3 + | + | |_| |_| 于是你会发现实际上我们的变换为递增序列,即把所有的环都变成自环,而交换两个数字即拆环,所以不难知道,一个环拆掉的最少的次数为环的大小-1(因为…

［抄题］: We have two integer sequences A and B of the same non-zero length. We are allowed to swap elements A[i] and B[i].  Note that both elements are in the same index position in their respective sequences. At the end of some number of swaps, A and B…

Swaps and Inversions Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3588    Accepted Submission(s): 976 Problem Description Long long ago, there was an integer sequence a.Tonyfang think this se…

6318.Swaps and Inversions 这个题就是找逆序对,然后逆序对数*min(x,y)就可以了. 官方题解:注意到逆序对=交换相邻需要交换的次数,那么输出 逆序对个数 即可. 求逆序对有4种操作,线段树 .BIT.归并排序.树状数组. 我敲了线段树.归并排序和树状数组版的. 关于这几种方法求逆序对,自行百度吧,懒了... 代码(线段树版-注意排序): //1010-找逆序对数-线段树求逆序对数 #include<iostream> #include<cstdio>…

交换相邻两数 如果只是交换相邻两数,那么最少交换次数为该序列的逆序数. 交换任意两数 数字的总个数减去循环节的个数?? A cycle is a set of elements, each of which is in the place of another.  So in example sequences { 2, 1, 4, 3}, there are two cycles: {1, 2} and {3, 4}.  1 is in the place where 2 needs to G…

题目链接: D. Swaps in Permutation time limit per test 5 seconds memory limit per test 256 megabytes input standard input output standard output You are given a permutation of the numbers 1, 2, ..., n and m pairs of positions (aj, bj). At each step you ca…

题目链接:A. Sereja and Swaps 题意:给定一个序列,能够交换k次,问交换完后的子序列最大值的最大值是多少 思路:暴力枚举每一个区间,然后每一个区间[l,r]之内的值先存在优先队列内,然后找区间外假设有更大的值就替换掉. 求出每一个区间的最大值,最后记录下全部区间的最大值 代码: By lab104_yifan, contest: Codeforces Round #243 (Div. 2), problem: (C) Sereja and Swaps, Accepted, #…

http://codeforces.com/contest/691/problem/D D. Swaps in Permutation   You are given a permutation of the numbers 1, 2, ..., n and m pairs of positions (aj, bj). At each step you can choose a pair from the given positions and swap the numbers in that…

D. Two Strings Swaps time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given two strings aa and bb consisting of lowercase English letters, both of length nn. The characters of both…

Swaps and Inversions Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2787    Accepted Submission(s): 1071 Problem Description Long long ago, there was an integer sequence a.Tonyfang think this s…

原题链接在这里:https://leetcode.com/problems/minimum-swaps-to-make-sequences-increasing/ 题目: We have two integer sequences A and B of the same non-zero length. We are allowed to swap elements A[i] and B[i].  Note that both elements are in the same index pos…

We have two integer sequences A and B of the same non-zero length. We are allowed to swap elements A[i] and B[i].  Note that both elements are in the same index position in their respective sequences. At the end of some number of swaps, A and B are b…