J. Bottles time limit per test 2 seconds memory limit per test 512 megabytes input standard input output standard output Nick has n bottles of soda left after his birthday. Each bottle is described by two values: remaining amount of soda ai and bottl…

<题目链接> 题目大意: 有n个瓶子,各有水量和容量.现在要将这写瓶子里的水存入最少的瓶子里.问你最少需要的瓶子数?在保证瓶子数最少的情况下,要求转移的水量最少. 解题分析:首先,最少的瓶子数肯定可以通过贪心来简单求解.然后就是将所有瓶子的水量作为01背包的总体积,然后就是$dp[i][j]$表示前$i$个物品选了水量为$j$的最大容量.本题的这种逆向思维有点像那道小偷抢银行的01背包题.但是因为本题规定了需要选取的那些容量大的物品,所以略有不同.对这$n$个物品进行01背包,杯子的水量看成体…

http://codeforces.com/problemset/problem/730/J 题意:有n个瓶子,每个瓶子有一个当前里面的水量,还有一个瓶子容量,问要把所有的当前水量放到尽量少的瓶子里至少需要几个瓶子,还有最少需要倒的水量(把一个瓶子的水倒到另一个瓶子的总水量). 思路:是一个背包dp,dp[i][j] 表示选择i个瓶子容量为j的时候当前拥有的最大的水量.不过第三层循环当时不知道应该怎么写. #include <cstdio> #include <cstring> #…

J. Bottles time limit per test 2 seconds memory limit per test 512 megabytes input standard input output standard output Nick has n bottles of soda left after his birthday. Each bottle is described by two values: remaining amount of soda ai and bottl…

J. Bottles time limit per test 2 seconds memory limit per test 512 megabytes input standard input output standard output Nick has n bottles of soda left after his birthday. Each bottle is described by two values: remaining amount of soda ai and bottl…

http://codeforces.com/contest/730/problem/J 3 4    36    1 90   45   40 其实可以知道,选出多少个瓶子呢?是确定的,当然选一些大的. 那么问题转化为: 在n个瓶子中,选出k个,然后把剩余的n - k个瓶子得液体转移过去这k个里面,费用最小.其实就是使得剩余的n - k个瓶子的拥有液体数最小,那么其实就是需要那k个瓶子得拥有液体数最多. dp[i][k][j]表示在前i个物品中,选出了k个物品,产生的总容量是j的时候,拥有液体数…

题目链接: http://codeforces.com/problemset/problem/671/A 题目大意: A和B在一张二维平面上,平面上有N个垃圾,垃圾桶只有一个在T,问把所有垃圾全扔进垃圾桶最少走多远.一次只能拿一个垃圾.允许一个人走另一个人停下来. (1 ≤ n ≤ 100 000)  (0 ≤ xi, yi ≤ 109) 题目思路: [模拟] 因为每次只能携带一个垃圾,大部分垃圾都是人扔完上一个垃圾后,从垃圾桶出发去捡的. 而最多有两个垃圾不是被人从垃圾桶出发完再扔到垃圾桶.…

暴力. 每个人找到一个入口,也就是从回收站到这个入口走的路程由人的位置到入口的路程来替代. 因此,只要找两个人分别从哪里入口就可以了.注意:有可能只要一个人走,另一人不走. #pragma comment(linker, "/STACK:1024000000,1024000000") #include<cstdio> #include<cstring> #include<cmath> #include<algorithm> #includ…

题目链接:http://codeforces.com/problemset/problem/671/A 题目大意:给你两个人的位置和一个箱子的位置,然后给出n个瓶子的位置,要求让至少一个人去捡瓶子放到箱子里面去,一次只能拿一个瓶子,求把全部瓶子捡完之后的距离总和最小.解题思路:开始有两个起点A,B.除了从A或B出发拿瓶子并回到箱子距离不确定,其他时候肯定要从箱子到瓶子再回到箱子,距离就是dis(箱子到瓶子)*2.关于从A,B出发拿瓶子,分三种情况:①只有A拿②只有B拿③A拿一个瓶子,B拿一个瓶子…

J. Rising Sun time limit per test 1.0 s memory limit per test 1024 MB input standard input output standard output Joon has a midterm exam tomorrow, but he hasn't studied anything. So he decided to stay up all night to study. He promised himself that…

J.The Keys Out of all science labs constructed by the GEMA mission on Mars, the DSL - Dangerous Species Lab is the most dangerous of them all. The laboratory is so dangerous that you have to go through N doors in succession to get to it. Each one of…

 Problem J Judging Moose 这个题是这里面最简单的一个题... 代码: 1 //J 2 #include <stdio.h> 3 #include <math.h> 4 #include <string.h> 5 #include <stdlib.h> 6 #include <iostream> 7 #include <sstream> 8 #include <algorithm> 9 #includ…

J Just A Minim 超级无敌大水题,但是被精度卡了一手,输出要精确到小数点后6位,我直接输出的... 代码: 1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<cmath> 5 #include<queue> 6 #include<set> 7 #include<algorithm> 8 #include<map&g…

感觉很简单,就是讨论一下 #include <stdio.h> #include <string.h> #include <algorithm> #include <math.h> using namespace std; typedef pair<double,int>pii; ; double x[N],y[N]; pii a[N],b[N]; double dis(double x1,double y1,double x2,double y…

A.Toda 2 思路:可以有二分来得到最后的数值,然后每次排序去掉最大的两个,或者3个(奇数时). /************************************************ *Author* : Ray(siludose) *Created Time* : 2016��10��24�� ����һ 15ʱ00��28�� **Problem** : /media/ray/708898B888987E72/Users/Administrator/Desktop/2016…

题目链接:http://codeforces.com/problemset/problem/730/J 题目大意:有n个杯子, 每个杯子有两个值一个是已装水量,一个是可装水量.从一个杯子向另一个杯子倒1单位体积的水,时间花费为1s. 现在用n个杯子中的s个来装所有水, 求最小的s, 以及最少花费的时间. 解题思路:有了n杯水的总水量, 可以按照n个杯子的大小排序, 然后就可以求出最小的s.然后就可以将题目看做是求从n个杯子里面选s个,这s个杯子的总的可装水量是大于等于总水量,这种情况下这n个杯子…

J. Bottles time limit per test 2 seconds memory limit per test 512 megabytes input standard input output standard output Nick has n bottles of soda left after his birthday. Each bottle is described by two values: remaining amount of soda ai and bottl…

熟练掌握dp的定义方法. ①四维dp的转移,生命值转移时候需要注意的 ②集合的定义,判断二进制内部是否有环 ③很难想到的背包问题 ④博弈类型的dp ⑤排列组合类型dp ⑥01背包的变种(01背包+完全背包) ⑦codeforces Good bye 2016 E 线段树维护dp区间合并 ⑧ ⑨ ⑩ ⑪ ⑫ ⑬ ⑭ ⑮ ⑯ ⑰ ⑱ ⑲ ⑳ 一:http://www.cnblogs.com/heimao5027/p/5988770.html 四维dp 或者 剪枝 + dfs Codeforces B…

A. Toda 2 按题意模拟即可. #include <bits/stdc++.h> using namespace std ; typedef pair < int , int > pii ; #define clr( a , x ) memset ( a , x , sizeof a ) const int MAXN = 105 ; pii a[MAXN] ; int G[MAXN * MAXN][MAXN] ; int n , x ; void solve () { int…

A. Toda 2 题意:给你n个人,每个人的分数是a[i],每次可以从两个人到五个人的使得分数减一,使得最终的分数相等: 思路:假设答案为m:每个人的分数与答案m的差值为d[i],sum为d[i]的总和,max为d[i]的最大值:仅当sum-max>=max的时候才满足: 满足之后,总和为奇数,先取三个,再取两个(都是最大与次大值):偶数每次取两个即可: B. Minimum and Maximum 题意:人机交互题:给你一个数组 ,找出其中的最小值与最大值,需要在询问f(n)的次数内得到最大…

题目链接:http://codeforces.com/problemset/problem/315/A 题目意思:有n个soda bottles,随后给出这n个soda bottles的信息.已知第 i 个bottle来自品牌ai,你可以用这个品牌 ai 来开所有属于品牌bi 的bottles.注意,other特别用黑色粗体来强调,表明该行的除外,也就是说,假如i = 1(隐含的),ai = 1,bi = 1,这个bottle 1 是不能被打开的.需要找出无论用什么方式都不能打开的bottle的…

A. Recycling Bottles 题目连接: http://www.codeforces.com/contest/671/problem/A Description It was recycling day in Kekoland. To celebrate it Adil and Bera went to Central Perk where they can take bottles from the ground and put them into a recycling bin.…

C. Recycling Bottles   It was recycling day in Kekoland. To celebrate it Adil and Bera went to Central Perk where they can take bottles from the ground and put them into a recycling bin. We can think Central Perk as coordinate plane. There are n bott…

J. Deck Shuffling Time Limit: 2   Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/gym/100187/problem/J Description The world famous scientist Innokentiy continues his innovative experiments with decks of cards. Now he has a deck of n cards and k…

Problem J. Triatrip Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/gym/100342/attachments Description The travel agency “Four Russians” is offering the new service for their clients. Unlike other agencies that only suggest one-way…

链接:http://codeforces.com/gym/101116 题意:给出n个点,要求一个矩形框将(n/2)+1个点框住,要面积最小 解法:先根据x轴选出i->j之间的点,中间的点(包括两边)按照y排序,固定一边X=(xj-xi),Y就枚举点两端的Y坐标,细节是注意要取(n/2)+1个点 事实上这样取里面一定符合要求 #include <iostream> #include <cstdio> #include <algorithm> #include &l…

题目链接: http://codeforces.com/gym/100342 题意: 求三元环的个数 题解: 用bitset分别统计每个点的出度的边和入度的边. 枚举每一条边(a,b),计算以b为出度的边的终点构成的点集和以a为入度的边的起点够成的点集的交集,更新答案. 代码: #include<iostream> #include<cstring> #include<cstdio> #include<bitset> using namespace std;…

题目链接: http://codeforces.com/gym/100114 Description The computer network of “Plunder & Flee Inc.” consists of n servers and m two-way communication links. Two servers can communicate either through a direct link, or through a chain of links, by relayi…

Problem J. Bye Bye RussiaTime Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/gym/100500/attachments Description It was the last day at Russia, after the World Finals has ended. Coach fegla was travelling back to Cairo on the same day b…

J. Computer Network Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/gym/100114 Description The computer network of “Plunder & Flee Inc.” consists of n servers and m two-way communication links. Two servers can communicate either thr…