这场BC实在是有趣啊,T2是个没有什么算法但是细节坑的贪心+分类讨论乱搞,T3反而码起来很顺. 然后出现了T2过的人没有T3多的现象(T2:20人,T3:30人),而且T2的AC率是惨烈的不到3% (我T2读入写挂,思路想挂,推倒重码一次,交了7次才过QAQ) 最后狂码T3赶在结束之前调出来过了,3题最后都没有被叉也没有fst,捡了个rk9,人品好啊. 题意 给出26个字母的一个排列,对一个字符串进行一次变换表示将某个字母变成排列中对应的字母. 例如zabcdefg....wxy,1表示经过一次…

MG loves string  Accepts: 30  Submissions: 67  Time Limit: 2000/1000 MS (Java/Others)  Memory Limit: 262144/262144 K (Java/Others) 问题描述 MG是一个很忙碌的男孩子.今天他沉迷于这样一个问题: 对于一个长度为N的由小写英文字母构成的随机字符串,当它进行一次变换,所有字符i都会变成a[i]. MG规定所有a[i]构成了26个字母组成的排列. MG现在需要知道这个随机串…

MG loves string Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 131    Accepted Submission(s): 50 Problem Description MG is a busy boy. And today he's burying himself in such a problem: For a…

MG loves string Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others) Problem Description MG is a busy boy. And today he's burying himself in such a problem: For a length of N, a random string made of lowercase letters…

MG loves string    Accepts: 30    Submissions: 67  Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others) 问题描述 MGMG是一个很忙碌的男孩子.今天他沉迷于这样一个问题: 对于一个长度为NN的由小写英文字母构成的随机字符串,当它进行一次变换,所有字符ii都会变成a[i]a[i]. MGMG规定所有a[i]a[i]构成了2626个…

题链: http://acm.hdu.edu.cn/showproblem.php?pid=6021 题解: 题意:对于一个长度为 N的由小写英文字母构成的随机字符串,当它进行一次变换,所有字符 i 都会变成a[i].同时变换数组:a[i]是26个字母组成的排列.现在需要知道这个随机串变换到自身的期望变换次数.请你输出期望答案乘上26^N以后模 1000000007的结果. 容斥,LCM 其实题目要求的就是每种串(共有 26^N种串)回到自身的变化次数之和. 暴力求法就是:看每种串的每个字符在循…

题目链接:点击传送 MG loves apple Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others) Problem Description MG is a rich boy. He has n apples, each has a value of V(0<=V<=9). A valid number does not contain a leading zero, and…

MG loves gold  Accepts: 451  Submissions: 1382  Time Limit: 3000/1500 MS (Java/Others)  Memory Limit: 262144/262144 K (Java/Others) Problem Description MG is a lucky boy. He is always be able to find gold from underground. It is known that the gold i…

MG loves gold Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others) Total Submission(s): 1607    Accepted Submission(s): 659     Problem Description MG is a lucky boy. He is always be able to find gold from underground…

MG loves apple  Accepts: 20  Submissions: 693  Time Limit: 3000/1500 MS (Java/Others)  Memory Limit: 262144/262144 K (Java/Others) 问题描述 MGMG是一个财富爆表的男孩子.他拥有N(1<=N<=100000)N(1<=N<=100000)个苹果,每个苹果上标有一个数字00~99,代表它的价值. 一个合法的数字是不含有前导零的,这nn个苹果恰好排成了一个…