Problem Statement Alice has a string s of lowercase letters. The string is written on a wall. Alice also has a set of cards. Each card contains a single letter. Alice can take any card and glue it on top of one of the letters of s. She may use any su…
Problem Statement You are given two ints: n and m. Let D be the number of permutations of the set {1,2,-,n+m} such that the first m values are not fixed points of the permutation. Formally, we are interested in permutations p such that for each j bet…
Problem Statement You are given a vector t that describes a rectangular table of zeroes and ones. Each character in t is either '0' or '1'. We say that a table is nice if there are two sequences x, y of zeroes and ones such that for each valid pair o…
# [Codeforces #312 div2 A]Lala Land and Apple Trees 首先,此题的大意是在一条坐标轴上,有\(n\)个点,每个点的权值为\(a_{i}\),第一次从原点开始走,方向自选(<- or ->),在过程中,若遇到一个权值>0的点,则将此权值计入答案,并归零.当次.此方向上的所有点均为0后,输出此时的答案. 然后,进行分析: 我们很容易想到这是一个贪心,我们将正的和负的分别存入两个数组,最初的方向为: \(zhengsum > fusum…
Problem Statement A string of zeros and ones is called an alternating string if no two adjacent characters are the same. Examples of alternating strings: "1", "10101", "0101010101". You are given a string s. Each character of…
Problem Statement You are given four ints: n, k, x, and y. The ints n and k describe a simple undirected graph. The graph has n nodes, numbered 1 through n. Two distinct vertices i and j are connected by an edge if and only if gcd(i, j) > k. Here, gc…
链接:http://codeforces.com/contest/984/problem/C 题意 三个数p, q, b, 求p/q在b进制下小数点后是否是有限位. 思路 题意转化为是否q|p*b^x,即看b和q有没有相同的质因子.如果用筛选质因子的话1e18的数会超时,所以每次求出b和q的gcd,再让q/gcd,如果q最后是1那么b和q拥有相同质因子,输出Finite,反之Infinite. 附代码: #include <bits/stdc++.h> typedef long long LL…
