枚举灯的所有可能状态(亮或者不亮)(1<<20)最多可能的情况有1048576种 dp[i]表示 i 状态时灯所能照射到的最远距离(i 的二进制中如果第j位为0,则表示第j个灯不亮,否则就是亮) 当i&(1<< j)时代表第i个状态灯j不亮,此时可由状态i转移到状态 i ^ ( 1 << j) 即dp[(i^(1<<j))]=max(dp[(i^(1<<j))],get(dp[i],j)) get是从dp[i]的位置开始第j个灯所能照亮的…

主题链接~~> 做题情绪:时候最后有点蛋疼了,处理点的坐标处理晕了.so~比赛完清醒了一下就AC了. 解题思路: 状态压缩DP ,仅仅有 20 个点.假设安排灯的时候仅仅有顺序不同的问题.全然能够用状态压缩去递推出来,仅仅是处理点的坐标的时候非常麻烦,理清思路就好了. 状态方程: dp [ S | (1 << i ) ]  = max( dp[ S |( 1 << i ) ] , dp[ S ] + W )  , 在状态 S 的情况下再加入 i 点(S 中先前不含 i 点),…

题目链接~~> 做题感悟:这题属于想法题,比赛时直接做的 D 题.可是处理坐标处理的头晕眼花的结果到最后也没AC. 解题思路: 由于查询的时候仅仅考虑素数,so~我们仅仅考虑素数就能够,这就须要筛素数.我们能够在筛素数的同一时候把某个素数出现的倍数加上.输入的时候仅仅要记录某个数的个数就能够了. 代码: #include<iostream> #include<sstream> #include<map> #include<cmath> #include…

385D - Bear and Floodlight 题目大意:有一个人从( l , 0 ) 想走到 ( r , 0 ),有 n 盏路灯,位置为( xi , yi ),每盏路灯都有一个照射的角度ai 这个角度内的区间都被照亮,问你走之前任意调路灯的方向,这个人只能走路灯照亮的地方,问你他最多能往 r 方向走多少距离. 思路:本来我想的是才20盏灯直接枚举灯的顺序也不会超时的吧,复杂度才20!* 20 (ps:我错了我是猪,20!复杂度很高), 结果GG,T掉了,改成状态压缩就过了,状态压缩也跑了…

Bear and Floodlight Time Limit: 4000MS   Memory Limit: 262144KB   64bit IO Format: %I64d & %I64u [Submit]   [Go Back]   [Status] Description One day a bear lived on the Oxy axis. He was afraid of the dark, so he couldn't move at night along the plane…

读懂题意发现是傻逼状压. 只要会向量旋转,以及直线求交点坐标就行了.(验证了我这俩板子都没毛病) 细节蛮多. #include<cstdio> #include<algorithm> #include<cstring> #include<cmath> using namespace std; const double PI=acos(-1.0); #define EPS 0.00000001 struct Point { double x,y; Point(…

time limit per test1 second memory limit per test256 megabytes inputstandard input outputstandard output Limak is a little bear who loves to play. Today he is playing by destroying block towers. He built n towers in a row. The i-th tower is made of h…

Description Recently, the bear started studying data structures and faced the following problem. You are given a sequence of integers x1, x2, ..., xn of length n and m queries, each of them is characterized by two integers li, ri. Let's introduce f(p…

题目链接: C. Bear and Prime 100 time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output This is an interactive problem. In the output section below you will see the information about flushing the outpu…

题目链接: B. Bear and Finding Criminals //#include <bits/stdc++.h> #include <vector> #include <iostream> #include <queue> #include <cmath> #include <map> #include <cstring> #include <algorithm> #include <cstd…