[CEOI2017]Building Bridges 有 \(n\) 个桥墩,高 \(h_i\) 重 \(w_i\).连接 \(i\) 和 \(j\) 消耗代价 \((h_i-h_j)^2\),用不到的桥墩被拆除,代价为 \(w_i\).求使 \(1\) 与 \(n\) 联通的最小代价. 数据范围:\(2\le n\le 10^5\),\(0\le h_i,|w_i|\le 10^6\). 非常经典的李超线段树维护 \(\texttt{dp}\) 的题目,小蒟蒻来分享一下. 很明显 \(w_i\…

Luogu4655 [CEOI2017]Building Bridges 有 \(n\) 根柱子依次排列,每根柱子都有一个高度.第 \(i\) 根柱子的高度为 \(h_i\) . 现在想要建造若干座桥,如果一座桥架在第 \(i\) 根柱子和第 \(j\) 根柱子之间,那么需要 \((h_i-h_j)^2\) 的代价. 在造桥前,所有用不到的柱子都会被拆除,因为他们会干扰造桥进程.第 \(i\) 根柱子被拆除的代价为 \(w_i\) . 现在政府想要知道,通过桥梁把第 \(1\) 根柱子和第 \(…

loj#2483. 「CEOI2017」Building Bridges 链接 https://loj.ac/problem/2483 思路 \[f[i]=f[j]+(h[i]-h[j])^2+(sum[i-1]-sum[j])\] \[f[i]=f[j]+h[i]^2+h[j]^2-2*h[i]*h[j]+sum[i-1]-sum[j]\] \[sum[j]-f[j]-h[j]^2=(-2*h[j])*h[i]+sum[i-1]+h[i]^2-f[i]\] \[f[j]+h[j]^2-sum[…

Building bridges Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 65535/32768 K (Java/Others)Total Submission(s): 45    Accepted Submission(s): 39 Problem Description Hululu and Cululu are two pacific ocean countries made up of many islands. T…

Building Bridges(build) 题目描述 A wide river has nn pillars of possibly different heights standing out of the water. They are arranged in a straight line from one bank to the other. We would like to build a bridge that uses the pillars as support. To ac…

题目传送门:LOJ #2483. 题意简述: 有 \(n\) 个数,每个数有高度 \(h_i\) 和价格 \(w_i\) 两个属性. 你可以花费 \(w_i\) 的代价移除第 \(i\) 个数(不能移除第 \(1\) 个和第 \(n\) 个数). 这之后,没有被移除的数中,相邻两个数 \(i\) 和 \(j\) 会产生 \((h_j-h_i)^2\) 的代价. 求最小代价. 题解: 斜率优化 DP. 考虑 \(\mathrm{f}[i]\) 表示只考虑前 \(i\) 个数的最小代价,易得转移 \…

http://poj.org/problem?id=2749 (这个约翰的奶牛真多事…………………………) i表示u与s1连,i+n表示u与s2连. 老规矩,u到v表示取u必须取v. 那么对于互相打架的奶牛u,v,有: add(u,v+n);add(v,u+n); add(u+n,v);add(v+n,u); 对于互为朋友的奶牛u,v,有: add(u,v);add(v,u); add(u+n,v+n);add(v+n,u+n); 但这远远不够,我们需要求最大值最小…… 二分?但是我们怎么边处理…

P2872 [USACO07DEC]道路建设Building Roads 题目描述 Farmer John had just acquired several new farms! He wants to connect the farms with roads so that he can travel from any farm to any other farm via a sequence of roads; roads already connect some of the farms…

http://www.kimballgroup.com/2012/02/design-tip-142-building-bridges/ The dominant topologies of Data Warehouse modelling (Star, Snowflake) are designed with one-to-many relationships in mind. Query readability, performance, and structure degrades sev…

题意 题目链接 Sol \[f[i], f[j] + (h[i] - h[j])^2 + (w[i - 1] - w[j]))\] 然后直接套路斜率优化,发现\(k, x\)都不单调 写个cdq就过了 辣鸡noi.ac居然出裸题&&原题 #include<bits/stdc++.h> #define Pair pair<double, double> #define MP(x, y) make_pair(x, y) #define fi first #define…