目录 @description@ @solution@ @accepted code@ @details@ @description@ 一个无穷大的方格图,每个方格内都种了棵树. 一开始点燃了 n 棵树.之后的每一秒内,火都会从一个格子蔓延到共边或者共顶点的方格.t 秒后,火停止蔓延. 记 val(x, y) 为方格 (x, y) 被点燃的时间,如果未被点燃,则 val(x, y) = 0. 求所有格子的 val 之和.模 998244353. Input 第一行两个整数 n 和 t (1≤n≤…

CF1086F Forest Fires 有点意思的题目 直接统计每个格子的val是非常难办的.很难知道每秒新出来多少个格子 设$F[i]$表示,前i时刻覆盖的格子的数量 则,$ans=\sum_{i=1}^T i*(F[i]-F[i-1])=T*F[T]-\sum_{i=0}^{T-1} F[i]$ 考虑$\sum_{i=0}^{T-1} F[i]$怎么求 $F[i]$可以是矩形面积并,但是不能暴力求,T太大 一起求? 麻烦的事情自然是两个点代表的正方形在某个时刻相交了 考虑相交之后的面积并的…

目录 问题引入 思考 Lagrange 插值法 插值过程 代码实现 实际应用 「洛谷 P4781」「模板」拉格朗日插值 「洛谷 P4463」calc 题意简述 数据规模 Solution Step 1 Step 2 证明 代码 「CF 995F」Cowmpany Cowmpensation 题意简述 数据规模 Solution Step 1 Step 2 证明 代码 「CF 662F」The Sum of the k-th Powers 题意简述 数据规模 Solution 代码 「BZOJ 3…

Python 爬取所有51VOA网站的Learn a words文本及mp3音频 #!/usr/bin/env python # -*- coding: utf-8 -*- #Python 爬取所有51VOA网站的Learn a words文本及mp3音频 import os import sys import time import urllib as req from threading import Thread import urllib2 import urllib from thre…

本节的内容来源:https://www.dataquest.io/mission/10/plotting-basics 本节的数据来源:https://archive.ics.uci.edu/ml/datasets/Forest+Fires 原始数据展示(这张表记录了某个公园的火灾情况,X和Y代表的是坐标位置,area代表的是烧毁面积) import pandas forest_fires = pandas.read_csv('forest_fires.csv') print(forest_fi…

机器学习数据集,主数据集不能通过,人脸数据集介绍,从r包中获取数据集,中国河流数据集   选自Microsoft www.tz365.Cn 作者:Lee Scott 机器之心编译 参与:李亚洲.吴攀.杜夏德 要学习怎么使用微软 Azure 机器学习,最重要的是获取样本数据集和进行实验. 在微软,我们有大量的样本数据集可用.这些数据集已经在 Azure Cortana Intelligence Gallery 中的样本模型中得到了应用. 其中一些数据集可以通过 Azure Blob 存储获取,所以…

Blue skies were finally visible in the capital on Thursday after the region suffered fromseven straight days of intense pollution, sending consumers out in droves to buy pollution masks. in droves:陆陆续续,成群结队 Although Thursday’s weather brought a colle…

1．A private conversation Last week I went to the theatre. I had a very good seat. The play was very interesting. I did not enjoy it. A young man and a young woman were sitting behind me. They were talking loudly. I got very angry. I could not hear th…

$课文53  触电的蛇 544. At last firemen have put out a big forest fire in California. 消防队员们终于扑灭了加利福尼亚的一场森林大火. 545. Since then, they have been trying to find out how the fire began. 从那时起,他们一直试图找出起火的原因. 546. Forest fires are often caused by broken glass or by…

My heart, the bird of the wilderness, has found its sky in your eyes. 我的心是旷野的鸟,在你的双眼中找到了天空.His main goal will be to make sure there is no chance of recurrence of pain in his back. The medals for the Tokyo 2020 Olympics and Paralympics will be made fr…