A. Island Puzzle time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output A remote island chain contains n islands, labeled 1 through n. Bidirectional bridges connect the islands to form a simple c…

B. Island Puzzle time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output A remote island chain contains n islands, labeled 1 through n. Bidirectional bridges connect the islands to form a simple c…

A. Orchestra time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Paul is at the orchestra. The string section is arranged in an r × c rectangular grid and is filled with violinists with the ex…

B. Island Puzzle time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output A remote island chain contains n islands, labeled 1 through n. Bidirectional bridges connect the islands to form a simple c…

题目:http://codeforces.com/contest/936/problem/C 玩了一个小时,只能想出 5*n 的方法. 经过一番观察?考虑这样构造:已经使得 A 串的一个后缀 = B 串的一个前缀,考虑再把一个正确的字符挪到 A 串的最后面. 设该字符为 x .它之前有 len 个字符.当前已经弄好的结尾长度为 l2 . 进行这5个操作:n-len , len , n-len-l2 , l2 , n-l2+1 . 思路就是: 1&2:使得 x 变成结尾: 3:使 x 变成开头.原…

由于换了台电脑,而我的贪心 & 构造能力依然很拉跨,所以决定再开一个坑( 前传: 贪心/构造/DP 杂题选做 u1s1 我预感还有Ⅲ(欸,这不是我在多项式Ⅱ中说过的原话吗) 24. P5912 [POI2004]JAS 一开始直接莽了个点分治,当我测过了样例美滋滋地一交,发现自己获得了 20 分的好成绩之后,才发现事情有那么亿点点不对劲( 不难发现,题目等价于求高度最小的点分树的高度,直接求有点困难,我们不妨来对其进行一些转化:我们考虑给每个点一个标号,那么问题可以转化为,求使得任意两个标号相同…

暴力 A - Orchestra import java.io.*; import java.util.*; public class Main { public static void main(String[] args) { Scanner cin = new Scanner (System.in); int r = cin.nextInt (); int c = cin.nextInt (); int n = cin.nextInt (); int k = cin.nextInt ();…

模拟枚举... A - New Year and Buggy Bot(http://codeforces.com/problemset/problem/908/B) 暴力枚举即可,但是直接手动暴力会非常繁琐,所以用到了STL,next_permutation(a,a+4),这个函数便是对a内元素进行全排列. #include<bits/stdc++.h> #define N 100000 #define ll long long using namespace std; ]; ][],s[];…

D. Bad Luck Island time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output The Bad Luck Island is inhabited by three kinds of species: r rocks, s scissors and p papers. At some moments of time two…

D:Bad Luck Island 一个岛上有r个石头,s个剪子,p个布,他们之间随机挑出两个相遇,如果不是相同物种,就会有一个消失,分别求出最后这座岛上只剩下一个物种的概率. 我们用dp[i][j][k]来存储剩下 i 个石头, j 个剪刀,k 个布时的概率,共dp三次: 如果石头与剪刀碰面,概率是 p1 = i*j / (i*j+j*k+k*i),这种情况下,剪刀会被石头吃掉,所以石头的数目减少1,表现出来是dp[i-1][j][k] = p1*dp[i][j][k]  (dp的3的返回值均…