目录 PE 15 PE 76 PE 90 PE 577 PE 97 PE 364(坑) 待做 发现这个题库,很有意思,趁着还没有学习微积分,看不了书,赶快从头开始刷,所以都是一些简单的题目,即时简单,有一些结论还是很有意思的. 网上资料很少,有的找不到答案,所以只有硬着头皮做了. PE 15 一个网格图,只能向下,或者向右走,问从\((0,0)\)到\((n,m)\)到路径有多少条. 这里的结论是有\(C_{n+m}^n\). 证明:从0,0到n,m会往下走n步,往右走m步,把路径看成一个长度为…

http://codeforces.com/gym/101078 和ysy.方老师一起打的virtual 打的不是很好...下面按过题顺序放一下过的题的题(dai)解(ma). A 给两个1~n的排列,把它们割成尽量短的一些段,使得每一段sort之后一样. 随便写个hash了事(1min交是因为之前顺手写了这题) #include <iostream> #include <stdio.h> #include <math.h> #include <string.h&…

问题描述: Work out the first ten digits of the sum of the following one-hundred 50-digit numbers. 371072875339021027987979982208375902465101357402504637693767749000971264812489697007805041701826053874324986199524741059474233309513058123726617309629919422…

前面说点什么.. 为了完成日常积累,傻逼呵呵的我决定来一发codeforces 挑水题 泛做.. 嗯对,就是泛做.. 主要就是把codeforces Div.1的ABCD都尝试一下吧0.0.. 挖坑0.0.. Codeforces Round #360 A. NP-Hard Problem 就是一个二分图染色,判断是否为二分图而已.. B. Remainders Game 题意:有一个未知的\(x\)和已知\(x\ mod\ c_i\)的值,问是否能确定\(x\ mod\ k\)的值 考虑一下中…

上一次接触 project euler 还是2011年的事情,做了前三道题,后来被第四题卡住了,前面几题的代码也没有保留下来. 今天试着暴力破解了一下,代码如下: (我大概是第 172,719 个解出这道题的人) program 4 A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99.…

开始做 Project Euler 的练习题.网站上总共有565题,真是个大题库啊! # Project Euler, Problem 1: Multiples of 3 and 5 # If we list all the natural numbers below 10 # that are multiples of 3 or 5, we get 3, 5, 6 and 9. # The sum of these multiples is 23. # Find the sum of all…

本题来自 Project Euler 第19题:https://projecteuler.net/problem=19 ''' How many Sundays fell on the first of the month during the twentieth century (1 Jan 1901 to 31 Dec 2000)? Answer: 171 ''' from datetime import * firstDay = date(1901,1,1) lastDay = date(…

本题来自 Project Euler 第17题:https://projecteuler.net/problem=17 ''' Project Euler 17: Number letter counts If the numbers 1 to 5 are written out in words: one, two, three, four, five, then there are 3 + 3 + 5 + 4 + 4 = 19 letters used in total. If all th…

本题来自 Project Euler 第11题:https://projecteuler.net/problem=11 # Project Euler: Problem 10: Largest product in a grid # In the 20×20 grid below, four numbers along a diagonal line have been marked in red. # The product of these numbers is 26 × 63 × 78 ×…

本题来自 Project Euler 第4题:https://projecteuler.net/problem=4 # Project Euler: Problem 4: Largest palindrome product # A palindromic number reads the same both ways. # The largest palindrome made from the product # of two 2-digit numbers is 9009 = 91 × 9…