CVBB ACM Team 2020-2021:teams:intrepidsword

2020-2021:teams:intrepidsword:2014-tokyo-regional

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T19:55:43+0800

Contest Info date: 2021.09.19 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:2015-beijing-regional

Anonymous (anonymous@undisclosed.example.com) — 2020-07-17T16:21:25+0800

Contest Info date: 2020.07.16 13:00-18:00 practice link Solutions K. A Math Problem 题目大意：定义一个 $\mathbb{N}^{+}\to\mathbb{N}^{+}$ 的数论函数 $f$，满足 $f(1)=1$，$3f(n)f(2n + 1)=f(2n)(1 + 3f(n))$，$f(2n)<6f(n)$。给定 $n$ 和一个质数 $p$，对于每个 $i\in[0,p)$，求 $f(1)\sim f(n)$ 中有多少个模 $p$ 余 $i$。题解：$f(2n+1)=f(2n)\frac{1+3f(n)}{3f(n)}$。由于 $1+3f(n)$ 和 $3f(n)$ 互质，因此 $f(2n)$$3f(n)$$f(2n)=3f(n)$$\mathcal{O}(p\log n)$

2020-2021:teams:intrepidsword:2015-ncpc

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T20:01:32+0800

Contest Info date: 2021.09.27 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:2015-shanghai-regional

Anonymous (anonymous@undisclosed.example.com) — 2020-07-11T22:21:40+0800

Contest Info date: 2020.07.05 13:00-18:00 practice link Solutions C. Colorful Tree 题目大意：给你一棵树，每个结点有一个颜色。要求支持两种操作，一种是将某个结点的子树颜色全改为 $c$，一种是查询某个结点子树中不同颜色的数量。$u$$u$$c$$\mathcal{O}(n^{\frac{5}{3}})$$\mathcal{O}(n\log n)$$n\le3000$$\Sigma\le70$$\le$$dp$$dp[i][j][k][u][v]$$i$$i$$j$$i-1$$k$$u$$v$$1$$u$$dp[\Sigma+1][0][0][cnt[1]][0]=1$$dp[i][j+1][k][u+1][v]+=dp[i][j][k][u][v]$$dp[i][j+2][k][u][v+1]+=dp[i][j][k][u][v]*2(cnt[i]-j-1)$$dp[i][j+1][k+1][u+1][v]+=dp[i][j][k][u][v]*(cnt[i-1]-k)$$i=2$$u$$u+v…

2020-2021:teams:intrepidsword:2016-icpc-qingdao

Anonymous (anonymous@undisclosed.example.com) — 2021-08-27T17:49:16+0800

Contest Info date: 2021.02.05 ??:??-??:?? practice link Solutions L. Tower Attack 题目大意：给一棵树，每次询问删掉两条边，问剩余森林的直径。题解：考虑维护 dfs 序上的区间直径。给一个点集 $S$，设其最远两点分别为 $x,y$$z$$S$$w$$\text{dis}(z,w)$$\text{dis}(z,x)$$\text{dis}(z,y)$$x$$y$$z$$w$$x$$y$$v_{1}\to v_{2}\to\ldots\to v_{t}$$t\ge2$$v_{1}\to v_{t}$$x$$y$$z$$y$$z\to v_{t}\to y$$z$$w$$\text{dis}(x,w)>\text{dis}(x,y)$$z\to w$$x\to y$$z$$S$$x,y$$S_{1},S_{2}$$S_{1}\cup S_{2}$$x_{1},y_{1},x_{2},y_{2}$$2$$6$…

2020-2021:teams:intrepidsword:2016-ntu-wf-team-selection

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T19:54:51+0800

Contest Info date: 2020.08.06 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:2018-kaist-spring

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T20:00:58+0800

Contest Info date: 2021.09.26 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:2018-swerc

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T16:23:24+0800

Contest Info date: 2020.04.19 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:2019-2020taipei-hsinchu

Anonymous (anonymous@undisclosed.example.com) — 2021-08-27T16:53:50+0800

Contest Info date: 2021.05.03 ??:??-??:?? practice link Solutions A. Rush Hour Puzzle 题目大意：... 题解：...

2020-2021:teams:intrepidsword:2019-hdu-multi-1

Anonymous (anonymous@undisclosed.example.com) — 2021-08-27T17:00:10+0800

Contest Info date: 2021.05.10 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:2019-hdu-multi-2

Anonymous (anonymous@undisclosed.example.com) — 2020-06-15T02:03:45+0800

Contest Info date: 2020.06.14 13:00-18:00 practice link Solutions C. Coefficient 题目大意：给定函数 $f(x)=\frac{b}{c+e^{ax+d}}(a\neq0)$，求其在 $x_{0}=-\frac{d}{a}$ 处泰勒展开第 $n$ 项 $(x-x_{0})^{n}$ 的系数。答案对 $998,244,353$ 取模。具体地说，给定一个 $n$，你需要回答 $q$ 组询问，每次给出不同的 $a,b,c,d$$n,q\le5\times10^{4}$$\sum n,\sum q\le3\times10^{5}$$t=ax+d$$f(t)=\frac{b}{c+e^{t}}$$f(x)$$f(x)=\sum_{i=0}^{+\infty}\frac{f^{(i)}(t)t^{i}}{i!}=\frac{a^{i}f^{(i)}(t)(x-x_{0})^{i}}{i!}$$a^{n}\frac{f^{(n)}(t)}{n!}$$f(t)$$a^{n}$$n=0$$\frac{b}{c+1}$…

2020-2021:teams:intrepidsword:2019-hdu-multi-u-1

Anonymous (anonymous@undisclosed.example.com) — 2020-05-16T22:33:31+0800

TODO

2020-2021:teams:intrepidsword:2019-icpc-xuzhou

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T22:15:02+0800

Contest Info date: 2021.02.07 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:2019-nwerc

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T16:19:30+0800

Contest Info date: 2020.04.28 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:2019-zhejiang-provincial

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T19:26:32+0800

Contest Info date: 2021.04.12 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:2020-ccpc-online

Anonymous (anonymous@undisclosed.example.com) — 2020-09-25T23:31:38+0800

Contest Info date: 2020-09-20 12:00~17:00 2020中国大学生程序设计竞赛（CCPC） - 网络选拔赛 Solutions 1001. Art Class 题目大意：有 $n$ 次操作，每次操作往平面上加个矩形，其中矩形底边在 $x$ 轴上，每次操作后求矩形并的周长。题解：如果你把题意从周长读成了面积 : ) 那么就会发现是裸吉如一线段树。然而事实上周长仍然可以用吉如一线段树维护。$x$$2$$\sum_{i=-\infty}^{+\infty}|a_{i}-a_{i-1}|$$a_{i}$$i$$r$$l$$\mathcal{O}(n\log n)$$2$$n+1$$n$$u$$v$$\text{lcm}(u,v)$$2$$2$$\left(\sum_{i=2}^{n+1}i\right)+\left(\sum_{i=3,i\text{ is prime}}^{n+1}i\right)$$\text{min_25}$$p$$f(0),f(1),\cdots,f(n)$$f(1),\cdots,f(p-1)$$f(\omega^{0…

2020-2021:teams:intrepidsword:2020-hdu-multi-1

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T18:35:33+0800

Contest Info date: 2020.09.13 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:2020-hdu-multi-2

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T18:34:08+0800

Contest Info date: 2020.12.05 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:2020-hdu-multi-3

Anonymous (anonymous@undisclosed.example.com) — 2021-08-27T17:46:50+0800

Contest Info date: 2021.01.23 ??:??-??:?? practice link Solutions B. Lady Layton and Stone Game 题目大意：有若干堆石子，每次可以取若干堆合并在一起，代价为合并后堆的大小。但是，堆数必须在 $L$ 和 $R$ 之间。求最小代价。$x$$y$$x>y$$x\le y$$x-1$$y+1$$x,y$$x-1,y+1$$\sum_{i=1}^{x}a_{i}\le a_{x+y}$$\sum_{i=1}^{x}a_{i}+\sum_{i=1}^{x+y-1}a_{i}$$\sum_{i=1}^{x-1}a_{i}+\sum_{i=1}^{x+y-1}a_{i}$$x-1,y+1$$\sum_{i=1}^{x-1}a_{i}\le a_{x+y}$$\sum_{i=1}^{x}a_{i}+\sum_{i=x+1}^{x+y}a_{i}$$\sum_{i=1}^{x-1}a_{i}+\sum_{i=1}^{x+y-1}a_{i}$$\sum_{i=1}^{x}a_{i}$$\sum_{i=x+…

2020-2021:teams:intrepidsword:2020-hdu-multi-4

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T18:31:18+0800

Contest Info date: 2021.01.30 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:2020-icpc-seoul

Anonymous (anonymous@undisclosed.example.com) — 2021-06-14T13:42:24+0800

Practice link

2020-2021:teams:intrepidsword:2020-icpc-xiaomi-online-1

Anonymous (anonymous@undisclosed.example.com) — 2021-08-27T17:43:23+0800

Contest Info date: 2021.10.25 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:2020-nerc

Anonymous (anonymous@undisclosed.example.com) — 2021-06-14T13:39:58+0800

Practice link

2020-2021:teams:intrepidsword:2020-nowcoder-multi-1

Anonymous (anonymous@undisclosed.example.com) — 2020-07-16T23:07:30+0800

Contest Info date: 2020.07.12 12:00-17:00 practice link Solutions A. B-Suffix Array 题目大意：定义一个字符串的 B 函数为字符串到相同长度非负整数序列的映射，第 $i$ 个整数表示字符串中在 $i$ 前面与 $i$ 字符相同的字符之间的最小距离，如果前面没有和自己一样的字符则记为 0。求每个后缀的 B 序列的排名。$s_{a\ldots n}$$l$$B(s_{a\ldots n})_{l+1\ldots n-a} = B(s)_{a+l+1\ldots n}$$s_{a\ldots n}$$B(s)_{a+l+1\ldots n}$$N^{+}$$n$$\frac{n}{\min n}$$w$$\min_{u}\sum_{i=1}^{m}w_{i}\cdot\text{dis}(u,i!)$$\text{dis}(u,v)=\text{dep}(u)+\text{dep}(v)-2\text{dep}(u,v)$$(i-1)!$$i!$$i$$(i-1)!$$i!$$(i-1)!$$i$$A…

2020-2021:teams:intrepidsword:2020-nowcoder-multi-2

Anonymous (anonymous@undisclosed.example.com) — 2020-07-17T00:44:16+0800

Contest Info date: 2020.07.13 12:00-17:00 practice link Solutions A. All with Pairs 题目大意：定义 $f(s, t)$ 为 $s$ 的前缀与 $t$ 的后缀中，长度最长的公共元素的长度，给 $n$ 个串，求一下 $\sum_i \sum_j f^2(s_i, s_j)$。题解：一个串 $s$ 可能会有多个 border，考虑如何不重复计算贡献。容易想到对于 $s$$|s|^{2}-|b_{s}|^{2}$$b_{s}$$s$$n$$P$$O$$P$$Q$$Q$$O$$P$$D$$E$$$ D = -\frac{\left|\begin{array}{ccc} x_P^2 + y_P^2 & y_P \\ x_Q^2 + y_Q^2 & y_Q \end{array}\right|} {\left|\begin{array}{ccc} x_P & y_P \\ x_Q & y_Q \end{array}\right|}, \quad E = \frac{\left|\begin{array…

2020-2021:teams:intrepidsword:2020-nowcoder-multi-3

Anonymous (anonymous@undisclosed.example.com) — 2020-07-25T22:10:28+0800

Contest Info date: 2020-07-18 12:00~17:00 2020牛客暑期多校训练营（第三场） Solutions A. Clam and Fish 题目大意：题解： B. Classical String Problem 签到题。 C. Operation Love 题目大意：给你一个“手掌”的图形，可能会被平移和旋转，给的点会按正序或者逆序给出，问你所给的点组成了右手还是左手。$n$$m$$m$$m$$4n$$m$$a_i$$i$$p_i$$\{p_i\}$$i$$p_i \ne p'_i$$a_i$$a_i$$a_{i+1}$$a_1, \ldots, a_i$$a_{i+1}, \ldots, a_n$$a_{i+1} - a_{i}$$4$$6$$4$$6$$4$$6$$\frac{c}{d}-\frac{e}{f}=\frac{a}{b}$$a,b\le2\times10^{6}$$c,d,e,f$$d,f

2020-2021:teams:intrepidsword:2020-nowcoder-multi-4

Anonymous (anonymous@undisclosed.example.com) — 2020-07-28T22:56:41+0800

Contest Info date: 2020-07-18 12:00~17:00 2020牛客暑期多校训练营（第四场） Solutions A. Ancient Distance 题目大意：给个树，要你给这个树的 $K$ 个节点打个标记，每个点算一下到祖先中最近的被标记的点的距离（没有就是无穷大），取最大值作为费用。问你最小费用是多少。对每个 $K \in [1, n]$$h$$h$$h$$0$$n\le10^{5}$$\sum n\le10^{6}$$9$$n$$128$$9$$1$$0$$1$$9$$1$$10000\cdots$$9999\cdots$$1\sim n$$1$$>\frac{n}{2}$$2p$$n$$m$$5\%$$30\le n\le300,1\le m\le\lfloor\frac{n}{30}\rfloor$$\frac{n}{m}-\frac{2n}{20m}$$\frac{2n}{20m}$$\frac{2}{3}$…

2020-2021:teams:intrepidsword:2020-nowcoder-multi-5

Anonymous (anonymous@undisclosed.example.com) — 2020-07-29T01:13:31+0800

Contest Info date: 2020-07-25 12:00~17:00 2020牛客暑期多校训练营（第五场） Solutions B. Graph 题目大意：给你一棵带边权的树，你可以任意加边或删边，但是要保证每次操作后图连通、任意环的边权异或和为 $0$。求可能的最小边权和。$d[u]$$d[u]\oplus d[v]$$d[u]$$d[u]$$\log$$\mathcal{O}(n\log^{2}A)$$n,m,k$$k$$a,b$$\sum_{i=1}^{k}a_{i}=n$$\sum_{i=1}^{k}=m$$\prod_{i=1}^{k}\min(a_{i},b_{i})$$\prod_{i=1}^{k}\min(a_{i},b_{i})$$c_{i}\le a_{i}\land c_{i}\le b_{i}$$c$$c$$t$$c$$a,b$$c$$n-t$$m-t$$4$$1+\frac{1}{2}$$\frac{2}{3}$$dp$$dp[i][j][S]$$i$$j$…

2020-2021:teams:intrepidsword:2020-nowcoder-multi-6

Anonymous (anonymous@undisclosed.example.com) — 2020-08-09T17:32:06+0800

Contest Info date: 2020-07-27 12:00~17:00 2020牛客暑期多校训练营（第六场） Solutions A. African Sort 题目大意：给你一个排列，每次选一个子集 $S$，花费 $|S|$ 的代价将 $S$ 位置的所有元素随机打乱。问排好序的期望代价。题解：题解（不甚严谨地）证明了：最优策略为对排列的每个环分别操作，每个环全部打乱。这个结论我们比赛时也猜到了，具体证明请看题解。$f(n)$$n$$g(n)$$n$$$ \begin{aligned} f(n)&=g(n)+n(n>1)\\ g(n)&=\frac{1}{n!}\sum_{i=1}^{n}{n-1\choose i-1}(i-1)!(n-i)!(f(i)+g(n-i))\\ g(n)&=\frac{1}{n}\sum_{i=1}^{n}(f(i)+g(n-i))\\ \end{aligned} $$$n\times n$$2$$i$$2^{i-1}$$f_{n}=\prod_{i=1}^{n}(2^{n}-2^{i-1})$$2^{n}(2^{n}-1)f_{…

2020-2021:teams:intrepidsword:2020-nowcoder-multi-7

Anonymous (anonymous@undisclosed.example.com) — 2020-08-09T17:28:37+0800

Contest Info date: 2020-08-01 12:00~17:00 2020牛客暑期多校训练营（第七场） Solutions D. Fake News 签到题，只有 $1,24$ 满足要求。 I. Valuable Forests 题目大意：定义一个森林的价值为所有点的度数平方和。求所有 $n$ 个点带标号的森林的价值和。$1$$n\cdot\sum_{i=0}^{n-2}(i+1)^{2}{n-2\choose i}$

2020-2021:teams:intrepidsword:2020-nowcoder-multi-8

Anonymous (anonymous@undisclosed.example.com) — 2020-08-05T11:45:01+0800

Contest Info date: 2020-08-03 12:00~17:00 2020牛客暑期多校训练营（第八场） Solutions D. Disgusting Relationship 题目大意：对于一个 $n$ 和 $a_{1},\cdots,a_{n}$，定义 $f(a_{1},\cdots,a_{n})$ 表示对每个 $i$ 满足长为 $i$ 的环恰有 $a_{i}$ 个的 $n$ 的不同排列数。求满足 $f(a_{1},\cdots,a_{n})$ 不能被 $p$（$p$ 为质数）整除的 $\{a\}$$f$$$ \begin{aligned} f(a_{1},\cdots,a_{n})&=\frac{n!}{\prod_{i=1}^{n}(i!)^{a_{i}}}\cdot\prod_{i=1}^{n}((i-1)!)^{a_{i}}\cdot\frac{1}{\prod_{i=1}^{n}a_{i}!}\\ &=\frac{n!}{\prod_{i=1}^{n}i^{a_{i}}\cdot\prod_{i=1}^{n}a_{i}!} \end{align…

2020-2021:teams:intrepidsword:2020-nowcoder-multi-10

Anonymous (anonymous@undisclosed.example.com) — 2021-06-19T23:24:23+0800

G. Math Test 对不起，我数学太差了。题目大意：给定 $1\le a\le10^{5}$ 和 $1\le n\le10^{18}$，求有多少 $1\le x\le y\le n$ 满足 $\gcd(x,y)=1$，$x\mid y^{2}+a$，$y\mid x^{2}+a$。有 $10^{6}$ 组询问。题解：对于一组满足要求的 $x,y$，可以证明 $y,\frac{y^{2}+a}{x}$ 也满足要求。 $$ \begin{aligned} &\left(\frac{y^{2}+a}{x}\right)^{2}+a\\ =&\frac{y^{4}+2ay^{2}+a^{2}+ax^{2}}{x^{2}}\\ =&\frac{y^{4}+2ay^{2}+a(x^{2}+a)}{x^{2}} \end{aligned} $$ 显然能被 $y$ 整除。假设质数 $p$ 满足 $p\mid y,p\mid\frac{y^{2}+a}{x}$，那么 $p\mid a$$y\mid x^{2}+a$$p\mid x$$\gcd(y,\frac{y^{2}+a}{x})…

2020-2021:teams:intrepidsword:2020-nwerc

Anonymous (anonymous@undisclosed.example.com) — 2021-06-14T13:36:36+0800

Practice link

2020-2021:teams:intrepidsword:2020.05.01-2020.05.07_周报

Anonymous (anonymous@undisclosed.example.com) — 2020-05-16T22:22:40+0800

团队 2020.05.03 2019-2020 ICPC Asia Taipei-Hsinchu Regional Contest pro: 11/11/13 rk: 9/488 个人 zzh 2020.05.06 Codeforces Round 639 (Div. 1) pro:6/6 DONE 补题： 2020.04.15 Codeforces Round 635 (Div. 1) pro:6/7 pmxm jsh * 5/2 - Codeforces Round #393 (Div. 1): pro: 4/6 * 5/4 - AtCoder Beginner Contest 165: pro: 6/6 * 5/5 - 杂题 1000、1800，6 题一小时: $0, 1, \ldots$$f(c, i)$$c$$i$$u$$f$$f(u, *)$$f(u, i) \gets \sum_{v \ne u}{\sum_{j < i} f(v, j)}$$f(*, i)$$S(i)$$\mathcal{O}(n)$$f$$\sum_{u}{f(u, n)…

2020-2021:teams:intrepidsword:2020.05.08-2020.05.14_周报

Anonymous (anonymous@undisclosed.example.com) — 2020-05-17T21:44:00+0800

团队 2020.05.10: 2019 Multi-University Training Contest 1 pro: 8/9/13 rk: 15/1105 个人 zzh 2020.05.12 Codeforces Round 641 (Div. 1) pro:4/7 pmxm jsh * 5/8 - 牛客练习赛63: pro: 5/6/6 rk: 13/692 * 5/10 - Codeforces Round #641 (Div. 1): pro: 2/3/7 rk: 932/1213 * 5/14 - Codeforces Round #642 (Div. 3): $0$$g$$u$$h_u$$u$$g \oplus h_u$$0$

2020-2021:teams:intrepidsword:2020.05.15-2020.05.21_周报

Anonymous (anonymous@undisclosed.example.com) — 2020-05-24T15:08:23+0800

团队做毕设，摸了。个人 zzh Codeforces Round #643 (Div. 2): pro: 5/5/6 rk: 711/8876 pmxm 没摸 topcoder srm 722 (vp: solved solved opened) jsh * 5/15 - Codeforces Round #319 (Div. 1): pro: 3/3/5 (vp) * 5/16 - Codeforces Round #643 (Div. 2): pro: 5/5/6 rk: 136/8876 详细：2020.05.15-2020.05.21_周报本周推荐 zzh 科普一下解同余方程的基本思想吧。设 $f(\vec{x})\equiv a\pmod{m}$$m=p_{1}^{e_{1}}\cdots p_{s}^{e_{s}}$$f(\vec{x})\equiv a\pmod{p_{i}^{e_{i}}}$$p_{i}^{e_{i}}$…

2020-2021:teams:intrepidsword:2020.05.22-2020.05.28_周报

Anonymous (anonymous@undisclosed.example.com) — 2020-05-31T16:45:51+0800

团队做毕设，摸了。个人 zzh Codeforces Round #645 (Div. 2): pro: 5/6/6 rk: 80/18169 Educational Codeforces Round 88: pro: 5/6/6 rk: 159/14430 学习了一下 SA。 pmxm 本周没有打比赛 jsh 本周推荐 zzh Python：众所周知，Python 的整数是无限精度的，很多同学也可能知道 Python 有 decimal 处理浮点数。不过可能知道 Fraction 的人就不那么多了。例如 $n$$n$$n \le 8000$$i$$a_i$$a_i$$\mathcal{O}(n^2)$$A_i$$i$$a_i$\[{\displaystyle \left|\bigcap _{i=1}^{n}{\bar {A_{i}}}\right|=\left|S-\bigcup _{i=1}^{n}A_{i}\right|=|S|-\sum _{i=1}^{n}|A_{i}|+\sum _{1\leqslant i

2020-2021:teams:intrepidsword:2020.05.29-2020.06.04_周报

Anonymous (anonymous@undisclosed.example.com) — 2020-06-07T10:01:32+0800

团队做毕设，摸了。个人 zzh 下周答辩，彻底摸了。 pmxm jsh * 6/1 - AtCoder Beginner Contest 169: pro: 6/6 rk: 60/? 本周推荐 zzh pmxm jsh 还是菜，莫得什么推荐。介值定理有时候也会用到，即计数或者统计贡献时，某个量是连续变化的。

2020-2021:teams:intrepidsword:2020.06.05-2020.06.11_周报

Anonymous (anonymous@undisclosed.example.com) — 2020-06-13T01:11:48+0800

团队考试，摸了。个人 zzh pmxm jsh * 6/6 - AtCoder Beginner Contest 163: pro: 6/6 rk: 14/? * 6/7 - Codeforces Round #648 (Div. 2): pro: 6/6/7 rk: ?/? * 6/10 - AtCoder Beginner Contest 164: pro: 5/6/6 rk: 18/? * 6/11 - Educational Codeforces Round 89 (Rated for Div. 2): pro: 5/5/7 rk: ?/? 本周推荐 zzh pmxm jsh 咱们的知识点里也有线段树合并，但是怎么没能证一下复杂度呢？那下面我先证明一下线段树合并的复杂度，然后介绍一个稍微复杂点的应用情况。$i$$r_i$$k_i$$r_{i+1} = r_i - 2 + 1$$k_{i+1}$$-2 + 1 = -1$$k_i$$k_i - k_{i+1}$$(k_0 - k_1) + (k_1 - k_2) + \cdots$$\m…

2020-2021:teams:intrepidsword:2020.06.12-2020.06.18_周报

Anonymous (anonymous@undisclosed.example.com) — 2020-07-05T21:19:02+0800

团队 2020.06.14 2019 Multi-University Training Contest 2 pro: 8/10/12 rk: 11/874 个人 zzh pmxm jsh * 6/12 - 牛客练习赛65: pro: 3/4/6 rk: 16/445 * 6/13 - Tokio Marine & Nichido Fire Insurance Programming Contest 2020: pro: 4/4/6 rk: 357/5966 * 6/13 - Codeforces Round #649 (Div. 2): pro: 4/4/5 rk: 222/9003 * 6/14 - AtCoder Beginner Contest 170: pro: 6/6/6 rk: 157/10433 * 6/18 - Codeforces Global Round 8: pro: 4/4/9 rk: 1108/12358$S$$T$$S$$T$$S$$T$$n$$m$$a$$c$$b = a/4+c/3$$S$$T$$a + c$$a$$c$…

2020-2021:teams:intrepidsword:2020.06.19-2020.06.25_周报

Anonymous (anonymous@undisclosed.example.com) — 2020-07-07T17:52:15+0800

团队个人 zzh pmxm jsh * 6/20 - “歌尔创客杯”第二届哈尔滨理工大学（荣成）程序设计竞赛: 全水题 * 6/20 - Codeforces Round #651 (Div. 2): pro: 5/7/7 rk: 171/??? * 6/25 - Educational Codeforces Round 90 (Rated for Div. 2): pro: 5/7/7 rk: 156/??? 本周推荐 zzh pmxm jsh

2020-2021:teams:intrepidsword:2020.06.26-2020.07.02_周报

Anonymous (anonymous@undisclosed.example.com) — 2020-07-07T18:06:15+0800

团队个人 zzh pmxm jsh * 6/26 - 牛客练习赛66: pro: 4/6/6 rk: 12/??? * 7/1 - Codeforces Round #654 (Div. 2): pro: 5/6/7 rk: 502/??? 本周推荐 zzh pmxm jsh

2020-2021:teams:intrepidsword:2020.07.03-2020.07.09_周报

Anonymous (anonymous@undisclosed.example.com) — 2020-07-07T18:09:00+0800

团队 2020.07.05 2015 ACM-ICPC Asia Shanghai Regional Contest pro: 8/10/12 rk: 3/201 个人 zzh pmxm jsh * 7/3 - Codeforces Global Round 7: pro: 6/6/9 (vp) * 7/4 - Codeforces Global Round 8: pro: 4/6/9 rk: 455/??? 本周推荐 zzh pmxm jsh

2020-2021:teams:intrepidsword:2020.07.10-2020.07.16_周报

Anonymous (anonymous@undisclosed.example.com) — 2020-07-17T22:26:21+0800

团队 2020.07.12 2020牛客暑期多校训练营（第一场） pro: 4/10/10 rk: 42/1116 DONE 2020.07.13 2020牛客暑期多校训练营（第二场） pro: 8/11/11 rk: 17/1158 DONE 2020.07.16 2015 ACM-ICPC Asia Beijing Regional Contest pro: 8/8/11 rk: 3/202 个人 zzh 本周无个人训练。专题无比赛无题目无 pmxm 本周个人训练: codeforces 2600难度的题目10道 TCO 2015 round 1A/1B$dp_{k+1,n}$$$ dp_{i,j} = dp_{i,j-1} + dp[i-1][j]/j $$$n$$1 \le n \le 1,000$$W_{l, r}$$[l, r]$$x_i$$n$$\mathcal{O}(n^3)$$s_i = \oplus_{j \le i}{x_j}$$s_0$$n$$s_0$$s_0$$s_0 + s_i$$W_{1,i}$$s_0$$s_i$$…

2020-2021:teams:intrepidsword:2020.07.17-2020.07.23_周报

Anonymous (anonymous@undisclosed.example.com) — 2020-07-24T16:01:51+0800

团队 2020.07.23 2020-2021 BUAA ICPC Team Supplementary Training 01 (2015-2016 Petrozavodsk Winter Training Camp, Saratov SU Contest) pro: 7/8/11 2020.07.20 2020牛客暑期多校训练营（第四场） pro: 7/7/10 rk: 3/1111 2020.07.18 2020牛客暑期多校训练营（第三场） pro: 8/12/12 rk: 22/1174 DONE 个人 zzh 专题无比赛 2020.07.21 Codeforces Round 658 (Div. 1) pro:4/6/6 rank:74/1344 题目无 pmxm 专题 topcoder dynamic programming 补完 (200 300 400 500 600 700 800)$n$$i$$a_i$$i$$b_i$$i$$i$$((i + 1) \bmod n) + 1$$L$$W$$W$$E_W$$\left|E_W\righ…

2020-2021:teams:intrepidsword:2020.07.24-2020.07.30_周报

Anonymous (anonymous@undisclosed.example.com) — 2020-08-07T18:17:03+0800

团队 2020.07.30 XVI Open Cup named after E.V. Pankratiev. GP of Ukraine pro: 11/11/13 rk: 35/409 2020.07.27 2020牛客暑期多校训练营（第六场） pro: 7/8/11 rk: 27/1019 2020.07.25 2020牛客暑期多校训练营（第五场） pro: 6/10/11 rk: 24/1116 个人 zzh 专题无比赛无题目无 pmxm 专题无，哦比赛 * 2020/7/24 SRM 788 problems: 1/2/3 rank: 102/190$60$$1 \le n \le 2\,000$$x$$x$$x$$x$$y$$\theta \in (-\pi, \pi)$$(x, y)$$f_{x, y}(\theta) = x + y \tan{\theta}$$u = \tan{\theta} \in \mathbb{R}$$g_{x, y}(u) = x + y u$$g_{x, y}(u)$$\mathcal{O}(…

2020-2021:teams:intrepidsword:2020.07.31-2020.08.06_周报

Anonymous (anonymous@undisclosed.example.com) — 2020-08-07T18:24:52+0800

团队 2020.08.03 2020牛客暑期多校训练营（第八场） pro: 5/7/11 rk: 10/685 2020.08.01 2020牛客暑期多校训练营（第七场） pro: 8/8/10 rk: 5/1090 个人 zzh 专题比赛题目 pmxm 专题比赛题目 jsh 专题比赛 * 2020/07/31 yukicoder contest 259 problems: 5/6/7 * 2020/08/02 AtCoder Beginner Contest 174 problems: 6/6/6 * 2020/08/05 Codeforces Round #661 (Div. 3) problems: 6/7/7$n$$a, b, c$$n$$$n^2 = s (s - a) (s - b) (s - c)$$$2 s = a + b + c$$a, b$$c$$x = s - a$$y = s - b$$z = s - c$$$n^2 = x y z (x + y + z)$$$x, y$$z$$n$$x, y, z$$a, b…

2020-2021:teams:intrepidsword:front_page

Anonymous (anonymous@undisclosed.example.com) — 2023-03-16T00:19:33+0800

训练记录 2022.02.08 ICPC Camp PTZ-Shanghai 2022-Day 2 2022.02.07 ICPC Camp PTZ-Shanghai 2022-Day 1 2021.07.16 XXI Open Cup named after E.V. Pankratiev. Grand Prix of Krakow, Division 1. 2021.07.13 XXI Open Cup named after E.V. Pankratiev. Grand Prix of Belarus, Division 1. 2021.07.11 XXI Open Cup named after E.V. Pankratiev. Grand Prix of Suwon, Division 1. 2021.07.08 XXI Open Cup named after E.V. Pankratiev. Grand Prix of Nizhny Novgorod 2021.07.05 XXI Open Cup named after E.V. Pankratiev. G…

2020-2021:teams:intrepidsword:icpc-camp-ptz-shanghai-2022-day-1

Anonymous (anonymous@undisclosed.example.com) — 2022-02-07T23:13:07+0800

Contest Info date: 2022.02.07 14:00-19:00 practice link Solutions

2020-2021:teams:intrepidsword:icpc-camp-ptz-shanghai-2022-day-2

Anonymous (anonymous@undisclosed.example.com) — 2022-02-12T22:31:42+0800

Contest Info date: 2022.02.08 14:00-19:00 practice link Solutions

2020-2021:teams:intrepidsword:pengmaoxiaomin

Anonymous (anonymous@undisclosed.example.com) — 2020-07-27T09:20:29+0800

彭毛小民个人 boruvka算法

2020-2021:teams:intrepidsword:petrozavodsk-summer-2015

Anonymous (anonymous@undisclosed.example.com) — 2021-06-20T20:57:12+0800

Practice link Solutions B. Break Free 题目大意：一个人在 $(x,y)(y>0)$，他要走到 $x$ 轴上 $[0,a](a>0)$ 这个区间上某一点。他必须以 $v$ 的速度匀速直线运动。另外有 $m$ 只老虎，每只位于 $(x_{i},y_{i})(y_{i}\ge0)$，老虎可以以不超过 $u_{i}$ 的速度，向任意方向运动。问 $x$$u\ge v$$x$$x$$u

2020-2021:teams:intrepidsword:ru-winter-camp-2015-saratov-su

Anonymous (anonymous@undisclosed.example.com) — 2020-07-24T16:35:14+0800

Contest Info date: 2020-07-18 12:00~17:00 2020-2021 BUAA ICPC Team Supplementary Training 01 2015-2016 Petrozavodsk Winter Training Camp, Saratov SU Contest Solutions A. Three Servers 题目大意：3 台机器，我们要分配 $n$ 个任务给机器，每个任务分一个机器即可，占用该机器 $t_i$ 个单位的时间。3 个机器各自被占用的总时间中，我们需要让最大和最小的差尽可能小。问方案。$t_i$$t_i$$3$$t_i$$i$$u$$v$$n$$m_0$$g$$\alpha_i \in [0, \pi]$$i$$(L, 0)$$$ P\left(\vec{\alpha}, \lambda'_1, \lambda'_2\right) = \left(\sum_{i=1}^n{-m_0 l_i g \left(\frac{1}{2} l_i \cos{\alpha_i} + \sum_{j

2020-2021:teams:intrepidsword:strategy

Anonymous (anonymous@undisclosed.example.com) — 2021-04-28T11:54:49+0800

做每一道题时 * 读题一定要把样例画一下。 * wjj不要帮人抄漏抄错模板 * 写题之前先用算法过样例，中间过程的值记录，模拟题打表先手写好 * 不测样例提交 zzh*1，dyx*1，wjj*1 * 交题之前先看一遍代码（数组大小，变量名，函数数组嵌套，typo）$n,m$$dp$$dp$$0$$0$$0$$0$$0^{0}$$0^{mod-1}$$0$$0$$0$

2020-2021:teams:intrepidsword:xvi-open-cup-ukraine

Anonymous (anonymous@undisclosed.example.com) — 2020-07-31T15:47:29+0800

Contest Info date: 2020-07-30 13:11~18:11 XVI Open Cup named after E.V. Pankratiev. GP of Ukraine Solutions J. Joining Powers 题目大意：定义数列 $s_{ij}=j^{i}$，给你若干个 $s_{i}$，将它们归并起来（合并相同元素），问第 $n$ 个数。保证答案 $\le10^{17}$。题解：二分后转化为求 $1\sim\text{mid}$ 中有多少个元素。考虑容斥，答案为 $\sum_{S\neq\emptyset}(-1)^{|S|+1}\lfloor\sqrt[\text{lcm}(S)]{\text{mid}}\rfloor$$\text{lcm}$$60$$1$$1$$\text{lcm}$…

2020-2021:teams:intrepidsword:xx-open-cup-grand-prix-of-nanjing

Anonymous (anonymous@undisclosed.example.com) — 2021-06-14T13:41:37+0800

Practice link

2020-2021:teams:intrepidsword:xxi-open-cup-grand-prix-of-belarus-1

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T12:54:36+0800

Contest Info date: 2021.07.13 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:xxi-open-cup-grand-prix-of-krakow-1

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T12:51:35+0800

Contest Info date: 2021.07.16 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:xxi-open-cup-grand-prix-of-nizhny-novgorod

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T12:53:15+0800

Contest Info date: 2021.07.08 ??:??-??:?? practice link Solutions B. Lockout vs tourist 题目大意：一场比赛有 $n$ 道题，每题有一定的分值。你和 tourist 两个人参加，每题只有先通过的人能得分。每次你和 tourist 分别选一道题做，如果你们做了同一道题，tourist 会比你先做完，你什么都得不到，然后继续抢剩下的题。如果你们选择了不同的题，你可以得到你选的那道题的分，但是之后 tourist 会开启暴走模式，秒掉剩下所有的题。问最优情况下你能得多少分。$dp$$$ \begin{aligned} V&=\min_{\boldsymbol{q}\in Y^{*}}\max_{i=1}^{n}\sum_{j=1}^{n}a_{ij}q_{j}\\ &=\min_{\boldsymbol{q}\in Y^{*}}\max_{i=1}^{n}q_{i}b_{i}+(1-q_{i})a_{i}\\ &=\min_{\boldsymbol{q}\in Y^{*}}\max_{i=1}^{…

2020-2021:teams:intrepidsword:xxi-open-cup-grand-prix-of-suwon-1

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T12:55:57+0800

Contest Info date: 2021.07.11 ??:??-??:?? practice link Solutions

2020-2021:teams:intrepidsword:xxi-open-cup-grand-prix-of-tokyo

Anonymous (anonymous@undisclosed.example.com) — 2021-08-26T12:57:09+0800

Contest Info date: 2021.07.05 ??:??-??:?? practice link Solutions