WZJRJ28

DescriptionFor each integer i from 1 to n, you must print a string si of length n consisting of letters ‘a’ and ‘b’ only. The string si must contain exactly i distinct palindrome substrings. Two sub

Vanya wants to minimize a tree. He can perform the following operation multiple times: choose a vertex v, and two disjoint (except for v) paths of equal length a0 = v, a1, ..., ak, and b0 = v, b

题意：给一个N个点的完全图，让你输出k个边不重复的生成树。分析：如果k > n/2直接无解，否则我们用类似数学归纳法的方法构造；可以发现从2开始才有解，而且n每增加2其构造方案数才能+1，当n为奇数时，我们可以让第n个点直接向前边的点连边来继承n-1的所有方案;当n为偶数时，我们可以直接继承n-2的所有方案，并且让[1,(n-2)/2]的边连向n-1，[(n-2)/2+1,n-

Let's call an array consisting of n integer numbers a1, a2, ..., an, beautiful if it has the following property:consider all pairs of numbers x, y (x ≠ y), such that number x occurs in the a

B. Recover the Stringtime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard outputFor each string s consisting of characters '0' a

题意：给定一个长度为n的字符串（26个小写字母），让你再构造一个长度为n的字符串，使得两串的LCS最小。分析：选原串中出现次数最少的字母构造就可以了，可以证明这样一定是LCS最小。#include#include#include#include#include#include#include#include#include#include#include

题意：给n个点m条边的DAG，最多可以添加k条边，问添加后的图的最小拓扑序的最大值是多少。分析：开两个set，一个维护当前入度为0的所有点，一个用来维护需要被加边的点，然后对于第一个set中值最小的点，如果set中还有其他点且k还没用完，那么我们便直接把它扔进第二个set中待处理，否则直接将其打印出；如果第一个set中只有这一个点，我们便考虑能不能从第二个set中找一个最大的点

045. Richness of wordsTime limit: 0.5 secondMemory limit: 64 MBFor each integer i from 1 to n, you must print a stringsi of length n consisting of lowercase Latin letters.The stringsi

In graph theory, graph colouring is a special case of graph labelling.It is an assignment of labels traditionally called colours to edges of a graph.Here we consider the simplest form.Given an u