题目链接: https://vjudge.net/problem/1735276/origin 题目大意与思路: 题目的基本意思就是求一个矩形的最小面积. 这个可以用最大最小值, 将他们分为X和Y组.但是最大最小值有一个特殊情况,就是最大值和最小值在同一个组里,比如都在X组里 然后排序 这种情况我们可以确定一条边是x = a[2*n]-a[1]则需要我们用一个tm 现在只需要我们用这一条边乘上连续n进行比较,取最小值 下面是AC代码: #include <iostream> #include…

CF1012A Photo of The Sky 有 \(n\) 个打乱的点的 \(x,\ y\) 轴坐标,现在告诉你这 \(2\times n\) 个值,问最小的矩形面积能覆盖住n个点且矩形长和宽分别与 \(x,\ y\) 轴平行. \(n\leq10^5,\ 1\leq x,\ y\leq10^9\) 贪心 先将 \(a_i\) 升序排序,方便接下来的操作 设将这 \(2\times n\) 个值分配为 \((x_i,\ y_i)\) 则 \(ans=\min\{\max\{x_i-x_j\…

作为一个蒟蒻,\(\tt{CF}\)止步\(Div.2\;C\) 这个题主要考察思维,正解代码炒鸡短-- 以下大部分搬运自官方题解 题目大意: 给你一段长度为\(2n\)的数列,将这个数列分为两个可重集,每个集合有\(n\)个元素,使得这两个集合的极差之积最小,输出这个最小值 题解: 假设输入的数组为\(a[2n]\),为了方便,我们把要分成的两个可重集叫做\(X\)和\(Y\) 首先肯定要先\(sort\)一下,使得数组有序,方便操作(下文提到的数组都是有序的) 接下来就是分类讨论了: 第一种…

B. Urbanization 题目链接 http://codeforces.com/contest/735/problem/B 题面 Local authorities have heard a lot about combinatorial abilities of Ostap Bender so they decided to ask his help in the question of urbanization. There are n people who plan to move…

题目链接: http://codeforces.com/problemset/problem/268/E E. Playlist time limit per test 1 secondmemory limit per test 256 megabytes 问题描述 Manao's friends often send him new songs. He never listens to them right away. Instead, he compiles them into a play…

E. Ants in Leaves 题目连接: http://www.codeforces.com/contest/622/problem/E Description Tree is a connected graph without cycles. A leaf of a tree is any vertex connected with exactly one other vertex. You are given a tree with n vertices and a root in t…

Intervals 题目连接: http://codeforces.com/gym/100231/attachments Description 给你n个区间,告诉你每个区间内都有ci个数 然后你需要找一个最小的点集,使得满足这n个区间的条件 Input n 然后li,ri,ci Output 输出最小点集大小 Sample Input 5 3 7 3 8 10 3 6 8 1 1 3 1 10 11 1 Sample Output 6 Hint 题意 题解: 线段树+二分+贪心 首先我们贪心一…

B. Sail 题目连接: http://www.codeforces.com/contest/298/problem/B Description The polar bears are going fishing. They plan to sail from (sx, sy) to (ex, ey). However, the boat can only sail by wind. At each second, the wind blows in one of these directio…

F. Doomsday Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/gym/100187/problem/F Description Doomsday comes in t units of time. In anticipation of such a significant event n people prepared m vaults in which, as they think, it will…

A. Purification Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/329/problem/A Description You are an adventurer currently journeying inside an evil temple. After defeating a couple of weak zombies, you arrived at a square r…

A. Exams Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/480/problem/A Description Student Valera is an undergraduate student at the University. His end of term exams are approaching and he is to pass exactly n exams. Valera…

题目链接:http://codeforces.com/problemset/problem/462/B Appleman has n cards. Each card has an uppercase letter written on it. Toastman must choose k cards from Appleman's cards. Then Appleman should give Toastman some coins depending on the chosen cards…

http://codeforces.com/contest/798/problem/D http://blog.csdn.net/yasola/article/details/70477816 对于二维的贪心我们可以先让它变成其中一维有序,这样只需要重点考虑另一维,就会简单很多. 首先,对于题目要求的选择元素之和两倍大与所有元素之和,我们可以转化为选择元素之和大于剩下的.然后我们可以将下标按照a从大到小排序.然后选择第一个,之后每两个一组,选择b大的一个,如果n是偶数再选择最后一个. 至于这样写…

B. Game of the Rows time limit per test:1 second memory limit per test:256 megabytes input:standard input output:standard output Daenerys Targaryen has an army consisting of k groups of soldiers, the i-th group contains ai soldiers. She wants to brin…

A. Lesha and array splitting time limit per test:2 seconds memory limit per test:256 megabytes input:standard input output:standard output One spring day on his way to university Lesha found an array A. Lesha likes to split arrays into several parts.…

Figure: The house floats up in the sky by balloons. This picture is also used in 2018 KAIST RUN Spring Contest poster. In the year 2117, Professor Jaemin Yu developed a linear-time algorithm for TSP(Traveling Salesperson Problem). Not long after that…

B. Passwords 题目连接: http://codeforces.com/contest/721/problem/B Description Vanya is managed to enter his favourite site Codehorses. Vanya uses n distinct passwords for sites at all, however he can't remember which one exactly he specified during Code…

A. Increasing Sequence 题目连接: http://www.codeforces.com/contest/11/problem/A Description A sequence a0, a1, ..., at - 1 is called increasing if ai - 1 < ai for each i: 0 < i < t. You are given a sequence b0, b1, ..., bn - 1 and a positive integer…

A. Mafia Time Limit: 20 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/348/problem/A Description One day n friends gathered together to play "Mafia". During each round of the game some player must be the supervisor and other n - 1…

C. Woodcutters Time Limit: 20 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/545/problem/C Description Little Susie listens to fairy tales before bed every day. Today's fairy tale was about wood cutters and the little girl immediately s…

题目链接:http://codeforces.com/contest/854/problem/B 题意: 有n栋房子从1到n排成一排,有k栋房子已经被售出. 现在你要买一栋“好房子”. 一栋房子是“好房子”的要求:(1)没被售出 (2)至少有一栋已售出的房子与他相邻(有邻居) 问你可能的好房子总数量的最小值和最大值. 题解: 贪心. 最小值: 从第1栋房子开始紧挨着往右共k栋全都售出了,好房子只有一栋就是第k栋楼的右边一栋. 特判:k == 0 || n == k:没有好房子,输出0. 最大值:…

http://codeforces.com/contest/732/problem/D 这题我发现很多人用二分答案,但是是不用的. 我们统计一个数值all表示要准备考试的所有日子和.+m(这些时间用来考试) 那么这个all值就是理想的最小值.然后去前all个数找,贪心地复习最小的科目,然后有的考试的话,就优先考试. 如果经过这all天,复习完了(这个是肯定得),但是只是因为时间分配不好,导致没得考试(数据导致没得考试) 那么就暴力枚举后面的[all + 1, n].有得考试就去考试,刚好考完就直…

题目链接: http://codeforces.com/contest/911/problem/F 题目大意: 给你一棵树,每次挑选这棵树的两个度数为1的点,加上他们之间的边数(距离),然后将其中一个点去掉,问你边数(距离)之和最大可以是多少. 要求输出每次选择的两个点和删掉的点 题解: 贪心题,策略是每次选择一个度数为1的点和距离它较远的直径的端点(显然直径的端点度数为1),然后把这个点删掉保留直径的端点.直到只剩下直径的时候才开始删掉直径上的点 为什么?考虑到先删一个直径外的点再删直径的端点…

传送门:http://codeforces.com/contest/976/problem/E 参考:https://www.cnblogs.com/void-f/p/8978658.html 题意: 对于每一个生物,有一个ph值和伤害值.现在有a次使ph值乘2的机会,有b次是伤害值等于ph值得机会. 问最后能得到最大的伤害总和是多少. 思路:自己一开始也想的是贪心,但是贪的姿势不正确.明确,a次一定是给同一个生物放大的.但是至于是对哪一个生物放大,还是要用暴力一个一个去找,而不要对排序后第一个…

题目链接:http://codeforces.com/contest/798/problem/D 题意:给出两串长度为n的数组a,b,然后要求长度小于等于n/2+1的p数组是的以p为下表a1-ap的和乘以2 大于a数组全部数的总和,b也是同理. 题解:一看到这题一般会想到贪心,由于是二维的贪心,所以一定要想让一维有序,所以可以按照a先排一下序. 得到排序后的数组a',先加上a'然后在依次两两选择b大的加上. #include <iostream> #include <cstring>…

链接: https://codeforces.com/contest/1216/problem/B 题意: Recently Vasya decided to improve his pistol shooting skills. Today his coach offered him the following exercise. He placed n cans in a row on a table. Cans are numbered from left to right from 1…

https://codeforces.com/contest/1256 A:Payment Without Change[思维] 题意:给你a个价值n的物品和b个价值1的物品,问是否存在取物方案使得价值为s 题解:min(s/n,a)*n+b>=s?YES:NO #include<iostream> #include<cstdio> #include<cstdlib> #include<cmath> #include<algorithm>…

Codeforces 题目传送门 & 洛谷题目传送门 原来 jxd 作业里也有我会做的题 i 了 i 了 首先这种题目的套路就是先考虑对于一个固定的 \(c\),怎样求出得分最高的策略,而类似于这样的问题都考虑贪心求解,手玩几组数据就能发现最优方案是将所有题目按照 \(\dfrac{p_i}{t_i}\) 从大到小排列.简单证明一下,考虑按照 P4437 排列的套路,假设有两道题 \(i,j\) 满足 \(\dfrac{p_i}{t_i}>\dfrac{p_j}{t_j}\),那么将 \(i…

http://codeforces.com/problemset/problem/747/D 题意:有n天,k次使用冬天轮胎的机会,无限次使用夏天轮胎的机会,如果t<=0必须使用冬轮,其他随意.问最少的换胎次数. 思路:先数冬天的天数tol,如果天数>k的话,那么就不可能度过.否则,最坏情况下,每到冬天就换一次冬天轮胎,然后度过冬天就换夏天轮胎,所以答案是2*tol.然后考虑尽量让每段冬天连续,这样可以减少换胎次数,于是算出冬天之间的间隔,然后从小到大排序,每次减少一段间隔,ans就可-2.然…

n个数,用最少的次数来改变数字,使得1到m出现的次数的最小值最大.输出最小值和改变次数以及改变后的数组. 最小值最大一定是n/m,然后把可以改变的位置上的数变为需要的数. http://codeforces.com/problemset/problem/723/C Examples input 4 21 2 3 2 output 2 11 2 1 2 input 7 31 3 2 2 2 2 1 output 2 11 3 3 2 2 2 1 input 4 41000000000 100 7…