E. Rock Is Push You are at the top left cell (1,1) of an n×m labyrinth. Your goal is to get to the bottom right cell (n,m). You can only move right or down, one cell per step. Moving right from a cell (x,y) takes you to the cell (x,y+1), while moving…

[CodeForces - 1225E]Rock Is Push [dp][前缀和] 标签:题解 codeforces题解 dp 前缀和 题目描述 Time limit 2000 ms Memory limit 524288 kB Source Technocup 2020 - Elimination Round 2 Tags binary search dp *2200 Site https://codeforces.com/problemset/problem/1225/E 题面 Examp…

题意: 有n个员工,每个员工完成一件A任务和一件B任务的时间给出,问要完成x件A任务y件B任务所需的最短时间是多少 思路: DP + 二分我也是第一次见到,这个我只能说太难想了,根本想不到. dp[i][j]表示在t时间内前i个人完成j件A任务后所能完成B任务的最大数量. 代码中还有一些注释. //#define LOCAL #include <iostream> #include <cstdio> #include <cstring> using namespace…

题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=4123 题目大意: 给一棵树,n个节点,每条边有个权值,从每个点i出发有个不经过自己走过的点的最远距离Ma[i],有m个询问,每个询问有个q,求最大的连续节点区间长度ans,使得该区间内最大的M[i]和最小的M[j]之差不超过q. 解题思路一: 这套题目好卡时间. 树形dp+二分+单调队列,几个基本的知识点杂糅在一起. 先用树形dp求出从任意一点i出发的Ma[i].两遍dfs,第一遍求出每个节点为根…

Longest Ordered Subsequence Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 41944   Accepted: 18453 Description A numeric sequence of ai is ordered if a1 < a2 < ... < aN. Let the subsequence of the given numeric sequence (a1, a2, ...…

MAX Average Problem Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 5825    Accepted Submission(s): 1446 Problem Description Consider a simple sequence which only contains positive integers as…

/** 题目:poj3208 Apocalypse Someday 链接:http://poj.org/problem?id=3208 题意:求第K(K <= 5*107)个有连续3个6的数. 思路:数位dp+二分. dp[i][j]表示长度为i,前缀状态为j时含有的个数. j=0表示含有前导0: j=1表示前缀连续1个6 j=2表示前缀连续2个6 j=3表示前缀连续3个6 j=4表示前缀不是6: */ //#include<bits/stdc++.h> #include<cstr…

Constructing Roads In JGShining's Kingdom Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 13646    Accepted Submission(s): 3879 Problem Description JGShining's kingdom consists of 2n(n is no mor…

题目描述 Farmer John is at the market to purchase supplies for his farm. He has in his pocket K coins (1 <= K <= 16), each with value in the range 1..100,000,000. FJ would like to make a sequence of N purchases (1 <= N <= 100,000), where the ith p…

[Codeforces 865C]Gotta Go Fast(期望dp+二分答案) 题面 一个游戏一共有n个关卡,对于第i关,用a[i]时间通过的概率为p[i],用b[i]通过的时间为1-p[i],每通过一关后可以选择继续下一关或者时间清0并从第一关开始,先要求通过所有关卡的时间和不能超过R才算彻底通关,问直到彻底通关位置的游戏时间的期望值为多少 分析 二分从头开始通关的用时期望mid 设\(dp[i][j]\)表示通前i关,当前时间为j的期望,倒推期望. 若超时重新开始,则\(dp[i][j]…