CF1307G Cow and Exercise 给 \(n\) 点 \(m\) 边的带权有向图,边 \(i\) 为 \((u_i,v_i,w_i)\).\(q\) 次询问,每次给 \(x_i\),问修改一些边使整张图的边权和增加 \(x_i\) 后最短路最大值(可以把边权修改为浮点数). 数据范围:\(2\le n\le 50\),\(1\le m\le n\cdot (n-1)\),\(1\le u_i,v_i\le n\),\(1\le w_i\le 10^6\),\(1\le q\le…

题目大意   求在一张有\(m\)条边无向连通图中,点\(s\)到点\(t\)的经过\(k\)条边的最短路(\(1 \leq m \leq 100\),\(1 \leq k \leq 10^6\)).   题解   边数\(m\)很小,显然点数\(n\)也很小,不超过\(200\),我们可以先离散化处理.   我们可以得到\(n\)个点之间的邻接矩阵,其中矩阵中的\(a[i][j]\)就相当于点\(i\)到点\(j\)的经过\(1\)条边的最短路.   此时我们设\(dp[i][j][k']\)…

目录 description solution accepted code details description 给定 n 点 m 边简单有向图,有边权. q 次询问,每次给出 xi.可以增加某些边的边权,要求总增加量小于等于 xi,最大化点 1 到点 n 的最短路. 原题链接. solution 可以去看看dls表演如何正确切这道题:读完题发现是原题,找题解读了一遍,过了. 设答案的下界为 \(D\),边权增长量为 \(a_{u, v}\),最短路为 \(d_i\). 可以根据最短路的三角不…

A - Lake Counting POJ - 2386 最最最最最基础的dfs 挂这道题为了提高AC率(糖水不等式 B - Paint it really, really dark gray CodeForces - 717E dfs 待会写题解 C - New Year Transportation CodeForces - 500A 简单的模拟 D - Binary Tree Traversals HDU - 1710 给树的先序中序输出后序 贴下代码 #include <algorith…

问题 A: 毛一琛/$cow$ $subsets$ 时间限制: 1 Sec  内存限制: 512 MB 题面 题面谢绝公开. 题解 题名貌似是个大神??看起来像是签到题然后就死了. 首先$O(3^n)$算法显然.也显然过不去$20$的测试点. 正解是赫赫有名的$meet$ $in$ $the$ $middle$算法.数据在40以内的都能用$meet$ $in$ $the$ $middle$?? 对于两半路径,可以拼起来并且构成合法答案的条件是两人获得的分数相同. 所以一个比较聪明的办法是,不去记…

题目描述 The cows are having a picnic! Each of Farmer John's \(K (1 ≤ K ≤ 100)\) cows is grazing in one of \(N (1 ≤ N ≤ 1,000)\) pastures, conveniently numbered \(1...N\). The pastures are connected by \(M (1 ≤ M ≤ 10,000)\) one-way paths (no path connec…

题目 FJ's \(N (1 ≤ N ≤ 10,000)\) cows conveniently indexed 1..N are standing in a line. Each cow has a positive integer height (which is a bit of secret). You are told only the height \(H (1 ≤ H ≤ 1,000,000)\) of the tallest cow along with the index I…

题目 For their physical fitness program, \(N (2 ≤ N ≤ 1,000,000)\) cows have decided to run a relay race using the \(T (2 ≤ T ≤ 100)\) cow trails throughout the pasture. Each trail connects two different intersections \((1 ≤ I1_i ≤ 1,000; 1 ≤ I2_i ≤ 1,…

Problem Description Farmer John has been informed of the location of a fugitive cow and wants to catch her immediately. He starts at a point N (0 ≤ N ≤ 100,000) on a number line and the cow is at a point K (0 ≤ K ≤ 100,000) on the same number line. F…

http://www.lydsy.com/JudgeOnline/problem.php?id=1604 https://www.luogu.org/problemnew/show/P2906#sub 了解奶牛们的人都知道,奶牛喜欢成群结队．观察约翰的N(1≤N≤100000)只奶牛,你会发现她们已经结成了几个“群”．每只奶牛在吃草的时候有一个独一无二的位置坐标Xi,Yi(l≤Xi,Yi≤[1．.10^9]:Xi,Yi∈整数．当满足下列两个条件之一,两只奶牛i和j是属于同一个群的: 1．两只奶牛…