题目链接:http://codeforces.com/problemset/problem/734/C 题目大意:要制作n个药,初始制作一个药的时间为x,魔力值为s,有两类咒语,第一类周瑜有m种,每种咒语使制作一个药的时间变成a[i],花费b[i]的魔力,第二类咒语有k种,每种咒语瞬间产生c[i]个药,花费d[i]的魔力,c[i]和d[i]都是不递减的,求最短时间内产生n个药的时间.解题思路:因为c[i]和d[i]都是不降的,所以可以枚举a[i],然后二分查找花费小于t-b[i]的第二类咒语.注…

C. Anton and Making Potions 题目连接: http://codeforces.com/contest/734/problem/C Description Anton is playing a very interesting computer game, but now he is stuck at one of the levels. To pass to the next level he has to prepare n potions. Anton has a…

Anton is playing a very interesting computer game, but now he is stuck at one of the levels. To pass to the next level he has to prepare npotions. Anton has a special kettle, that can prepare one potions in x seconds. Also, he knows spells of two typ…

传送:http://codeforces.com/gym/101612 题意:给定一个数n(<=1e18),将n分解为若干个数的成绩.要求这些数两两之间的差值不能大于1. 分析: 若n==2^k,则答案一定是-1. 然后,考虑若n==a^k,枚举k,二分求a.若n==a^x*(a+1)^y,枚举x,y,二分求解a. 注意:两数相乘可能>1e18,特判. #include<bits/stdc++.h> using namespace std; typedef long long ll…

题目描述: Prime Gift time limit per test 3.5 seconds memory limit per test 256 megabytes input standard input output standard output Opposite to Grisha's nice behavior, Oleg, though he has an entire year at his disposal, didn't manage to learn how to sol…

http://codeforces.com/contest/734/problem/C 因为有两种操作,那么可以这样考虑, 1.都不执行,就是开始的答案是n * x 2.先执行第一个操作,然后就会得到一个time和left.就是你会得到一个新的用时,和一个剩下的魔法数,然后在第二个操作数中二分,二分第一个小于等于left的值,意思就是我现在还拥有left点魔法,能够买最多多少个技能的意思. 就是,看着样例一 得到的会是 time : 40s    80s 60s left   : 79 89 5…

题目链接:http://codeforces.com/contest/734/problem/C C. Anton and Making Potions time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Anton is playing a very interesting computer game, but now he i…

C. Anton and Making Potions time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Anton is playing a very interesting computer game, but now he is stuck at one of the levels. To pass to the next…

Anton and Making Potions time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Anton is playing a very interesting computer game, but now he is stuck at one of the levels. To pass to the next le…

CodeForce-734C Anton and Making Potions  C. Anton and Making Potions time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Anton is playing a very interesting computer game, but now he is stuck…

codeforces734C——Anton and Making Potions详解 Anton and Making Potions 题目描述(google翻译) 安东正在玩一个非常有趣的电脑游戏,但现在他被困在其中一个级别.为了进入下一个级别,他必须准备n个药水. 安东有一个特殊的水壶,可以在x秒内准备一个魔药.此外,他知道两种类型的法术可以加快准备魔药的过程. 这种类型的法术加速了一种魔药的准备时间.有这种类型的m个法术,其中第i个成本为bi manooints并且将每个药水的准备时间改为…

Anton and Making Potions time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Anton is playing a very interesting computer game, but now he is stuck at one of the levels. To pass to the next le…

Yukari's Birthday  HDU4430 就是枚举+二分: 注意处理怎样判断溢出...(因为题目只要10^12) 先前还以为要用到快速幂和等比数列的快速求和(但肯定会超__int64) 而且这样判断会超时的... 还有题目中的And it's optional to place at most one candle at the center of the cake. (中间的蜡烛可有可无) 还有观察数据就知道:因为n最大10^12,r最多枚举到40,然后二分k的结果,看是否有符合条…

1514: Packs Time Limit: 10 Sec  Memory Limit: 128 MBSubmit: 61  Solved: 4[Submit][Status][Web Board] Description Give you n packs, each of it has a value v and a weight w. Now you should find some packs, and the total of these value is max, total of…

The SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how many quadruplet (a, b, c, d ) ∈ A x B x C x D are such that a + b + c + d = 0 . In the following, we assume that all lists have the same size n .…

[Codeforces 865C]Gotta Go Fast(期望dp+二分答案) 题面 一个游戏一共有n个关卡,对于第i关,用a[i]时间通过的概率为p[i],用b[i]通过的时间为1-p[i],每通过一关后可以选择继续下一关或者时间清0并从第一关开始,先要求通过所有关卡的时间和不能超过R才算彻底通关,问直到彻底通关位置的游戏时间的期望值为多少 分析 二分从头开始通关的用时期望mid 设\(dp[i][j]\)表示通前i关,当前时间为j的期望,倒推期望. 若超时重新开始,则\(dp[i][j]…

time limit per test4 seconds memory limit per test256 megabytes inputstandard input outputstandard output Anton is playing a very interesting computer game, but now he is stuck at one of the levels. To pass to the next level he has to prepare n potio…

题目描述: Maximum Value time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You are given a sequence a consisting of n integers. Find the maximum possible value of (integer remainder of *a**i* divi…

https://codeforces.com/contest/1241/problem/C You are an environmental activist at heart but the reality is harsh and you are just a cashier in a cinema. But you can still do something! You have n tickets to sell. The price of the i-th ticket is pi.…

题目链接: B. Skills time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Lesha plays the recently published new version of the legendary game hacknet. In this version character skill mechanism was…

E. Simple Skewness time limit per test:3 seconds memory limit per test:256 megabytes input:standard input output:standard output Define the simple skewness of a collection of numbers to be the collection's mean minus its median. You are given a list…

题目链接:Prime Gift 题意: 给出了n(1<=n<=16)个互不相同的质数pi(2<=pi<=100),现在要求第k大个约数全在所给质数集的数.(保证这个数不超过1e18) 题解: 如果暴力dfs的话肯定超时间,其实给的n数据范围最大是16是一个很奇妙的数(一般折半枚举基本上是这样的数据范围@.@-).所以想到折半枚举,把所有的质数分成两份求出每份中所有小于1e18的满足条件的数.然后二分答案,写cheak函数时遍历第一个集合,对第二个集合二分(折半枚举基本上这个套路).…

A. Sagheer and Crossroads time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Sagheer is walking in the street when he comes to an intersection of two roads. Each road can be represented as two…

题目描述: Sagheer and Nubian Market time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output On his trip to Luxor and Aswan, Sagheer went to a Nubian market to buy some souvenirs for his friends and re…

B. Tennis Game time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Petya and Gena love playing table tennis. A single match is played according to the following rules: a match consists of mult…

You are given an array a consisting of n integers, and additionally an integer m. You have to choose some sequence of indices \(b_1, b_2, ..., b_k (1 ≤ b_1 < b_2 < ... < b_k ≤ n)\) in such a way that the value of \(\sum^{k}_{i=1}a_{b_i}\) is maxi…

题意: 有一个谷仓容量为\(n\),谷仓第一天是满的,然后每天都发生这两件事: 往谷仓中放\(m\)个谷子,多出来的忽略掉 第\(i\)天来\(i\)只麻雀,吃掉\(i\)个谷子 求多少天后谷仓会空 分析: 分类讨论: 1. \(n \leq m\) 每天都会把谷仓放满,所以第\(n\)后会变空 2. \(n > m\) 前\(m\)天后谷仓还一直都是满的 第\(m+1\)天后还剩\(n-m-1\),第\(m+2\)天后还剩\(n-m-1-2\) 第\(m+i\)天后还剩\(n-m-\frac{…

https://codeforces.com/contest/1121/problem/F 题意 给你一个有n(<=5000)个字符的串,有两种压缩字符的方法: 1. 压缩单一字符,代价为a 2. 压缩一个串,条件是这个串是前面整个串的连续子串,代价为b 题解 n<=5000 定义dp[i]为压缩前i个字符的代价,则答案为dp[n] dp[i]=min(dp[i-1]+a,min(dp[j]+b)(即[j+1,i]为[1,j]的子串)) 用字符串哈希处理判定一个串是否为前面的子串 坑点 串ab…

B. Lorry 题目连接: http://www.codeforces.com/contest/3/problem/B Description A group of tourists is going to kayak and catamaran tour. A rented lorry has arrived to the boat depot to take kayaks and catamarans to the point of departure. It's known that a…

http://codeforces.com/problemset/problem/760/B 题意:有n张床m个枕头,每张床可以有多个枕头,但是相邻的床的枕头数相差不能超过1,问第k张床最多能拥有的枕头数是多少.每张床至少有一个枕头. 思路:因为每张床至少需要一个枕头,所以先将m减掉n之后来考虑剩余枕头如何分配. 我们考虑一个最优的情况,假设有5张床,9个枕头,k为3的时候,那么这样分配:1 2 3 2 1,这样其实就如同阶梯一样,要让第k个最高,然后向两边递减. 我们可以二分答案,使用等差数列…