题解:So you want to be a 2n-aire1.题意地址:https://vjudge.net/problem/UVA-10900 The player starts with a prize of $1, and is asked a sequence of n questions. For each question, he may • quit and keep his...

题解 : Xor Sum 21.题意地址：https://vjudge.net/problem/AtCoder-arc098_b 1.1 Problem StatementThere is an integer sequence A of length N. Find the number of the pairs of integers l and r ($1 \leq l \leq r ...

题解 : 消失之物1.题意:地址：https://www.luogu.com.cn/problem/P4141 ftiasch 有 n 个物品, 体积分别是 $w_1,w_2,\dots,w_n$。由于她的疏忽，第 i个物品丢失了。 “要使用剩下的 n-1 物品装满容积为 x 的背包，有几种方法呢？”——这是经典的问题了。 她把答案记为 $\text{cnt}(i,x)$ ，想要得到所有$i...

题解:Incremental Induction这题的难点在于 1.阅读理解 2.统计答案时的思路 1.题意地址:https://vjudge.net/problem/Kattis-incrementalinductionThe Nordic Collegiate Pong Championship (NCPC) is an insanely competive tournament w...

线性筛(欧拉筛)1.关于欧拉筛用途：线性的求区间[1,n]的所有质数 事实上，优化以后的埃氏筛已经很优秀了，一般情况下，很难通过时间复杂度区分欧拉筛和埃氏筛。 所以我们为什么需要欧拉筛 欧拉筛可以完成很多计数，比如欧拉函数 欧拉筛比较高级且常数略小一些 2.原理和过程过程： 欧拉筛的主要思想是，用已知的质数筛掉这个质数的倍数。且需要保证对于任意一个合数，它会且只会它的最小因数筛掉 所以我...

题解:Space Rescuers>>模拟退火/二分1.题意：地址:https://vjudge.net/problem/CodeForces-106EThe Galaxy contains n planets, there are many different living creatures inhabiting each planet. And each crea...

题解:Parabolic sorting地址:https://vjudge.net/problem/Gym-102780K 1.题意：Professor R. is the greatest specialist in the field of discrete mathematics. He has already got bored with all the standard sorti...