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…

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…

[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\…

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…

LOJ 洛谷 \(f_i=s_{i-1}+h_i^2+\min\{f_j-s_j+h_j^2-2h_i2h_j\}\),显然可以斜率优化. \(f_i-s_{i-1}-h_i^2+2h_ih_j=f_j-s_j+h_j^2\),横坐标不单调可以\(CDQ\)分治或\(Splay\).具体见这里. 然后差不多就是个模板了. 注意算斜率乘1.0啊mmp. //645ms 8.14MB #include <cstdio> #include <cctype> #include <cs…

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 \…

题目 斜率优化思博题,不想写了 之后就一直\(95\)了,于是靠肮脏的打表 就是更新了一下凸壳上二分斜率的写法,非常清爽好写 就当是挂个板子了 #include<algorithm> #include<iostream> #include<cstring> #include<cstdio> #define re register #define LL long long #define max(a,b) ((a)>(b)?(a):(b)) #defin…