POJ 3069 Saruman's Army(萨鲁曼军) Time Limit: 1000MS   Memory Limit: 65536K [Description] [题目描述] Saruman the White must lead his army along a straight path from Isengard to Helm’s Deep. To keep track of his forces, Saruman distributes seeing stones, know…

 Saruman's Army Time Limit:1000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Submit Status Practice POJ 3069 Appoint description:  System Crawler  (2015-04-27) Description Saruman the White must lead his army along a straight path fro…

带来两题贪心算法的题. 1.给定长度为N的字符串S,要构造一个长度为N的字符串T.起初,T是一个空串,随后反复进行下面两个操作:1.从S的头部删除一个字符,加到T的尾部.2.从S的尾部删除一个字符,加到T的尾部.求你任意采取这两个步骤后能得到的最小字符串T 2.直线上有N个点,点i的位置是xi,这N个点中选择若干个做上标记,对于每个点,在他们距离为R的区域内必须带有标记点,求在满足这个条件的情况下,所需要标记点的最少个数. 1.POJ 3617 Best Cow Line http://poj.…

链接:http://poj.org/problem?id=3069 题解 #include<iostream> #include<algorithm> using namespace std; ; int N,R; // N是部队数,R是有效射程 int X[MAX]; void solve(){ sort(X,X+N); ,ans=; while(i<N){ // s是没有被覆盖的最左边的点的位置 int s=X[i++]; //一直向右前进直到距 s的距离大于 R的点,此…

地址 http://poj.org/problem?id=3069 题解 题目可以考虑贪心 尽可能的根据题意选择靠右边的点 注意 开始无标记点 寻找左侧第一个没覆盖的点 再来推算既可能靠右的标记点为一轮 我最开始就是轮次的操作理解错误 结果wa了 ac代码如下 #include <iostream> #include <vector> #include <algorithm> using namespace std; /* poj3069 题目大意:一个直线上有N个点.…

简单贪心. 从左边开始,找 r 以内最大距离的点,再在该点的右侧找到该点能覆盖的点.如图. 自己的逻辑有些混乱,最后还是参考书上代码.(<挑战程序设计> P46) /****************************************** Problem: 3069 User: Memory: 668K Time: 16MS Language: G++ Result: Accepted ******************************************/ #inc…

Saruman's Army Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 8477   Accepted: 4317 Description Saruman the White must lead his army along a straight path from Isengard to Helm’s Deep. To keep track of his forces, Saruman distributes se…

2015-09-06 萨鲁曼军队 问题大意:萨鲁曼白想要让他的军队从sengard到Helm’s Deep,为了跟踪他的军队,他在军队中放置了魔法石(军队是一条线),魔法石可以看到前后距离为R的距离,为了让魔法石发挥最大的效益,魔法石戴在军人的身上,问你怎么才能使用最少的石头 问题很清晰,思路也很清晰,这道题挺典型的,就是贪心算法, 很容易想到的就是我们只用在距离内找到最后的点(人),然后把魔法石放到其上面就行了,然后依次类推,最后就可以达到最少的数量 具体可以以2R为一次循环,在前R的区间内我…

直线上有N个点.点i的位置是Xi.从这N个点中选择若干个,给它们加上标记.对每一个点,其距离为R以内的区域里必须又带有标记的点(自己本身带有标记的点,可以认为与其距离为0的地方有一个带有标记的点).在满足这个条件的情况下,希望能为尽可能少的点添加标记.请问至少要有多少点被加上标记? #include "iostream" #include "algorithm" using namespace std; const int MAX_N = 1000; int N=6…

Saruman's Army Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 13242   Accepted: 6636 Description Saruman the White must lead his army along a straight path from Isengard to Helm's Deep. To keep track of his forces, Saruman distributes s…

Saruman's Army Time Limit : 2000/1000ms (Java/Other)   Memory Limit : 131072/65536K (Java/Other) Total Submission(s) : 3   Accepted Submission(s) : 2 Problem Description Saruman the White must lead his army along a straight path from Isengard to Helm…

Saruman's Army Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 6688   Accepted: 3424 Description Saruman the White must lead his army along a straight path from Isengard to Helm's Deep. To keep track of his forces, Saruman distributes se…

题目连接 Description Saruman the White must lead his army along a straight path from Isengard to Helm's Deep. To keep track of his forces, Saruman distributes seeing stones, known as palantirs, among the troops. Each palantir has a maximum effective rang…

题意:给出指路石的范围,问最小需要几个指路石可以覆盖所有的军队. 题解:排序一遍,然后扫出起始区间和终止区间,就可以求出最小的覆盖数了 ac代码: #include <iostream> #include <algorithm> #include <cstdio> #include <cstring> using namespace std; int main() { cin.sync_with_stdio(false); int n,m; ]; while…

Saruman's Army Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 5989   Accepted: 3056 Description Saruman the White must lead his army along a straight path from Isengard to Helm's Deep. To keep track of his forces, Saruman distributes se…

Saruman the White must lead his army along a straight path from Isengard to Helm's Deep. To keep track of his forces, Saruman distributes seeing stones, known as palantirs, among the troops. Each palantir has a maximum effective range of R units, and…

Saruman's Army Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 18794   Accepted: 9222 Description Saruman the White must lead his army along a straight path from Isengard to Helm’s Deep. To keep track of his forces, Saruman distributes s…

万恶之源 目录 题意 思路 贪心的原则是什么呢? 错解 正解 代码实现 书上的代码 我的代码 比较一下 问题 题意 给定若干个点的坐标,与范围R.每个点可以选择是否标记,标记后这个点的左右范围R内的所有点也会被标记,求为使所有点被标记,我们要主动标记多少个点. 思路 这题总感觉可以用搜索做,毕竟每个点的状态要么是1要么是0.但这是书上贪心的例题,那肯定得用贪心做啦. 贪心的原则是什么呢? 错解 首先我们的目标是尽可能少的标记,因此我们当然可以希望每次一次性标记的点越多越好,那么我们是不是可以遍历…

[POJ 3069](2586见下) 原题在此:http://poj.org/problem?id=3069 题目大意: 一个直线上有N个点.点i的距离是Xi.从这些点中选取若干个加上标记.要求:对于每个点,与其距离为R的范围内必有做标记的点(包括自身).求至少标记多少点才能满足要求. 输入:N, R,以及N个点各自距原点的距离(①不一定按照顺序,故需要排序 ②可以重叠). 输出:被标记的点的最少个数. 解题思路: 从最左边开始看,在距离为R的范围内,被标记的点一定在第一个点的右侧(或是自身).…

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[SinGuLaRiTy-1024] Copyright (c) SinGuLaRiTy 2017. All Rights Reserved. [POJ 2709] 颜料 (Painter) 题目描述 杂货店出售一种由N(3<=N<=12)种不同颜色的颜料,每种一瓶(50ML),组成的颜料套装.你现在需要使用这N种颜料:不但如此,你还需要一定数量的灰色颜料.杂货店从来不出售灰色颜料——也就是它不属于这N种之一.幸运的是,灰色颜料是比较好配置的,如果你取出三种不同颜色的颜料各x ml,混合起来就…

Halloween treats Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 7644   Accepted: 2798   Special Judge Description Every year there is the same problem at Halloween: Each neighbour is only willing to give a certain total number of sweets…

Find a multiple Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 7192   Accepted: 3138   Special Judge Description The input contains N natural (i.e. positive integer) numbers ( N <= 10000 ). Each of that numbers is not greater than 15000…

The Pilots Brothers' refrigerator Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 22286   Accepted: 8603   Special Judge Description The game “The Pilots Brothers: following the stripy elephant” has a quest where a player needs to open a…

Flip Game Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 37427   Accepted: 16288 Description Flip game is played on a rectangular 4x4 field with two-sided pieces placed on each of its 16 squares. One side of each piece is white and the…

Corn Fields Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 9806   Accepted: 5185 Description Farmer John has purchased a lush new rectangular pasture composed of M by N (1 ≤ M ≤ 12; 1 ≤ N ≤ 12) square parcels. He wants to grow some yumm…

Sum of Consecutive Prime Numbers Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 20050   Accepted: 10989 Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representatio…

Tree Recovery Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 11939   Accepted: 7493 Description Little Valentine liked playing with binary trees very much. Her favorite game was constructing randomly looking binary trees with capital le…

Seek the Name, Seek the Fame Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 17898   Accepted: 9197 Description The little cat is so famous, that many couples tramp over hill and dale to Byteland, and asked the little cat to give names t…

题目: poj 2352 Stars 数星星 题意:已知n个星星的坐标.每个星星都有一个等级,数值等于坐标系内纵坐标和横坐标皆不大于它的星星的个数.星星的坐标按照纵坐标从小到大的顺序给出,纵坐标相同时则按照横坐标从小到大输出. (0 <= x, y <= 32000) 要求输出等级0到n-1之间各等级的星星个数. 分析: 这道题不难想到n平方的算法,即从纵坐标最小的开始搜,每次找它前面横坐标的值比它小的点的个数,两个for循环搞定,但是会超时. 所以需要用一些数据结构去优化,主要是优化找 横坐…