A.Infinite Sequence time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Consider the infinite sequence of integers: 1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5.... The sequence is built in the…

题目链接: A. Infinite Sequence time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Vasya likes everything infinite. Now he is studying the properties of a sequence s, such that its first element is…

A. Infinite Sequence time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Consider the infinite sequence of integers: 1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5.... The sequence is built in the…

题意 一个序列是, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5....这样排的,求第n个是什么数字. 分析 第n个位置属于1到k,求出k,然后n-i*(i-1)/2就是答案了. 方法1:可以枚举k为i,当i*(i+1)/2大于等于n时,k就是i了. 方法2:先让k=floor(sqrt(2*n)),如果k*(k+1)/2<n,那正确的k应该+1. 代码 方法1的写法1: #include<cstdio> int main() { long long…

A. Infinite Sequence 题目连接: http://www.codeforces.com/contest/622/problem/A Description Consider the infinite sequence of integers: 1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5.... The sequence is built in the following way: at first the number 1 is wr…

A. Infinite Sequence 题目连接: http://www.codeforces.com/contest/675/problem/A Description Vasya likes everything infinite. Now he is studying the properties of a sequence s, such that its first element is equal to a (s1 = a), and the difference between…

A. Infinite Sequence time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Consider the infinite sequence of integers: 1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5.... The sequence is built in the…

A - Infinite Sequence  CodeForces - 622A 题目大意:给你一个这样的数列1,1,2,1,2,3,1,2,3,4,1,2,3,4,5....就是从1~n排列(n++).最后问你第n个位置是什么数字. 思路:如果你花点时间列数列的话会发现,1~n的最后一位对应的位置是1~n的和,那我们就大胆使用二分进行搜索这位数. #include<iostream> #include<algorithm> #include<cstdio> #incl…

[arc071f]Infinite Sequence(动态规划) 题面 atcoder 洛谷 题解 不难发现如果两个不为\(1\)的数连在一起,那么后面所有数都必须相等. 设\(f[i]\)表示\([i,n]\)的填法数,初值\(f[n]=n,f[n-1]=n*n\) 考虑转移, 首先可以这里填上一个大于\(1\)的数然后后面连续若干个\(1\),这一部分的方案数是\(\sum_{j=i+3}^n f[j]\),这个后缀和记录一下就好了,然而还漏了一部分,即如果\(i+a_i>n\),那么这里的…

题目链接:Codeforces 486E LIS of Sequence 题目大意:给定一个数组.如今要确定每一个位置上的数属于哪一种类型. 解题思路:先求出每一个位置选的情况下的最长LIS,由于開始的想法,所以求LIS直接用线段树写了,没有改,能够用 log(n)的算法直接求也是能够的.然后在从后向前做一次类似LIS.每次推断A[i]是否小于f[dp[i]+1],这样就能够确定该位 置是否属于LIS序列. 然后为第三类的则说明dp[i] = k的仅仅有一个满足. #include <cstdi…