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 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 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…

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…

[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…

Problem 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 written out, then the numbers from 1 to 2, then the numbers from 1 to…

Codeforces 601B. Lipshitz Sequence 题意:,q个询问,每次询问给出l,r,求a数组[l,r]中所有子区间的L值的和. 思路:首先要观察到,斜率最大值只会出现在相邻两点上,因此可以处理出d数组,d[i]=a[i]-a[i-1].则问题转化为求d数组在指定区间内,所有子区间的最大值的和.枚举子区间的复杂度是平方级别,显然是不能接受的,所以可以用单调栈预处理出每个d[i]可以成为最大值的最大区间(形象地说,也就是d[i]为最大值的域可以延伸到左.右各多远),用l,r数…

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…