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: 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…

POJ3285 River Hopscotch 此题是大白P142页(即POJ2456)的一个变形题,典型的最大化最小值问题. C(x)表示要求的最小距离为X时,此时需要删除的石子.二分枚举X,直到找到最大的X,由于c(x)=m时满足题意,所以最后输出的是ub-1或者lb(lb==ub-1 注意相邻距离小于x的要删除(此处不是小于等于),对于相邻的距离小于x的两个石子,当删除其中一个后,又会产生其他的相邻的石子,直接计数不好计数,不妨用两个标记last,cur,其中last表示上一个石子,cur…

[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 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…

一个不错的二分,注释在代码里 #include <stdio.h> #include <cstring> #include <algorithm> #include <cmath> #include <iostream> using namespace std; ///二分搜索答案,最大化最小值 int main() { int L,n,m; ]; while(~scanf("%d %d %d",&L,&n,&…

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…

Description Every year the cows hold an ≤ L ≤ ,,,). Along the river between the starting and ending rocks, N ( ≤ N ≤ ,) more rocks appear, each at an integral distance Di < Di < L). To play the game, each cow in turn starts at the starting rock and…

传送门 https://www.cnblogs.com/violet-acmer/p/9793209.html 题意: 有 N 块岩石,从中去掉任意 M 块后,求相邻两块岩石最小距离最大是多少? 题解: 二分答案(假设答案为res) 定义 l = 0 , r = L ; mid = (l+r)/2 ; 判断当前答案 mid 至少需要去除多少块岩石,如果去除的岩石个数 > M,说明当前答案mid > res,r=mid;反之,说明当前答案 mid <= res , l =mid; AC代码…