\(\mathtt{CF 687D}\) \(\mathcal{Description}\) 给你一个图有 \(n\) 个点 \((1 \leq n \leq 10^3)\) 和 \(m\) 条边 \((1 \leq m \leq \dfrac{n*(n-1)}{2})\) ,边有边权.给定 \(q\) 组询问,每次询问给定 \(l\) 和 \(r\),用编号为 \([l,r]\) 去构成图,使得两边端点在同一个部分的边的最大值最小. \(\mathcal{Solution}\) 看到题第一反应…

[CF687D]Dividing Kingdom II 题意:给你一张n个点m条边的无向图,边有边权$w_i$.有q个询问,每次给出l r,问你:如果只保留编号在[l,r]中的边,你需要将所有点分成两个集合,使得这个划分的代价最小,问最小代价是什么.一个划分的代价是指,对于所有两端点在同一集合中的边,这些边的边权最大值.如果没有端点在同一集合中的边,则输出-1. $n,q\le 1000,m\le \frac {n(n-1)} 2,w_i\le 10^9$ 题解:先考虑暴力的做法,我们将所有边按…

D. Dividing Kingdom II   Long time ago, there was a great kingdom and it was being ruled by The Great Arya and Pari The Great. These two had some problems about the numbers they like, so they decided to divide the great kingdom between themselves. Th…

D. Dividing Kingdom II 题目连接: http://www.codeforces.com/contest/687/problem/D Description Long time ago, there was a great kingdom and it was being ruled by The Great Arya and Pari The Great. These two had some problems about the numbers they like, so…

Long time ago, there was a great kingdom and it was being ruled by The Great Arya and Pari The Great. These two had some problems about the numbers they like, so they decided to divide the great kingdom between themselves. The great kingdom consisted…

题意:给你m条边,每条边有一个权值,每次询问只保留编号l到r的边,让你把这个图分成两部分 一个方案的耗费是当前符合条件的边的最大权值(符合条件的边指两段点都在一个部分),问你如何分,可以让耗费最小 分析:把当前l到r的边进行排序,从大到小,从大的开始不断加边,判断当前能否形成二分图,如果能形成二分图,继续加边 如果不能形成二分图,那当前边的权值就是最小耗费(是不是很眼熟) 思路很清晰,现在我们要解决的是如何判断可以形成二分图,有两种,一个是2染色当前图(肯定超时) 所以只剩一种方法,带权并查集…

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…

A. Adding Digits 枚举. B. Ancient Prophesy 字符串处理. C. Balls and Boxes 枚举起始位置\(i\),显然\(a_i \le a_j, 1 \le j \le n\), 同时\(i+1\)到\(x\)之间数需要大于\(a_i\),那么只要处理下区间最值即可. D. Black and White Tree 当\(s_i\)是最小值时,点\(i\)是个叶子节点,那么在不同颜色中的集合中找另一点连接即可. E. Dividing Kingdom…

Constructing Roads In JGShining's Kingdom Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 14635    Accepted Submission(s): 4158 Problem Description JGShining's kingdom consists of 2n(n is no mo…

Constructing Roads In JGShining's Kingdom Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 23467    Accepted Submission(s): 6710 Problem Description JGShining's kingdom consists of 2n(n is no mo…