E - River Hopscotch POJ - 3258 Every year the cows hold an event featuring a peculiar version of hopscotch that involves carefully jumping from rock to rock in a river. The excitement takes place on a long, straight river with a rock at the start and…

Every year the cows hold an event featuring a peculiar version of hopscotch that involves carefully jumping from rock to rock in a river. The excitement takes place on a long, straight river with a rock at the start and another rock at the end, L uni…

 去掉石头 题目大意:一群牛在河上的石头上跳来跳去,现在问你如何通过去掉M个石头,使得牛跳过石头的最短距离变得最大? 这一题比较经典,分治法的经典,二分法可以很方便处理这个问题,我们只要明白比较函数这个东西就可以了. 模板: while (……) { mid = (lb + rb) / ; if (Judge_C(……)) else rb = mid; } while判断条件可以根据是整形还是浮点型灵活变换,Judge_C就是比较函数,几乎所有的分治算法都可以这样归纳,我们只要找到合适的比较函数…

题目传送门 /* 二分:搜索距离,判断时距离小于d的石头拿掉 */ #include <cstdio> #include <algorithm> #include <cstring> #include <cmath> using namespace std; typedef long long ll; ; const int INF = 0x3f3f3f3f; ll a[MAXN]; int n, m; bool check(ll d) { ; ; ; i&…

River Hopscotch Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 11031   Accepted: 4737 Description Every year the cows hold an event featuring a peculiar version of hopscotch that involves carefully jumping from rock to rock in a river.…

River Hopscotch Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 5193 Accepted: 2260 Description Every year the cows hold an event featuring a peculiar version of hopscotch that involves carefully jumping from rock to rock in a river. The e…

River Hopscotch Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 21939 Accepted: 9081 Description Every year the cows hold an event featuring a peculiar version of hopscotch that involves carefully jumping from rock to rock in a river. The…

River Hopscotch Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 6697   Accepted: 2893 Description Every year the cows hold an event featuring a peculiar version of hopscotch that involves carefully jumping from rock to rock in a river. T…

[题意] 牛要到河对岸,在与河岸垂直的一条线上,河中有N块石头,给定河岸宽度L,以及每一块石头离牛所在河岸的距离, 现在去掉M块石头,要求去掉M块石头后,剩下的石头之间以及石头与河岸的最小距离的最大值. [解法] 用二分做,但是开始写了三个版本的二分,全都wa. 无赖看了别人的二分,还是不理解,为什么他们写的就能过. 反复思索后,终于明白了:关键在于题目求的是什么. 做题思想:二分所求的最小距离的最大值mid,记录可以去掉的石头块数cnt(注意:当相邻的石头的距离小于等于mid,就可以去掉),…

River Hopscotch 直接中文 Descriptions 每年奶牛们都要举办各种特殊版本的跳房子比赛,包括在河里从一块岩石跳到另一块岩石.这项激动人心的活动在一条长长的笔直河道中进行,在起点和距离起点 L 远的终点各有一块岩石 (1 ≤ L ≤ 10^9).在起点和终点之间,有 N 块岩石 (0 ≤ N ≤ 50000),每块岩石与起点的距离分别为 Di (0 < Di < L). 在比赛过程中,奶牛轮流从起点出发,尝试到达终点,每一步只能从一块岩石跳到另一块岩石.当然,实力不济的奶…