Subtree Removal 很显然不可能选择砍掉一对有祖先关系的子树.令$f_i$表示$i$子树的答案,如果$i$不被砍,那就是$a_i + \sum\limits_j f_j$:如果$i$被砍,那就是$-x$.取个$max$就好了. 时间.空间复杂度$O(n)$. #include <bits/stdc++.h> using namespace std; ; int tc, n, xx; int a[N]; vector<int> g[N]; long long f[N];…
Description A prominent microprocessor company has enlisted your help to lay out some interchangeable components(widgets) on some of their computer chips. Each chip’s design is an N × N square of slots. Oneslot can hold a single component, and you ar…
1.局部代码块 位置:位于类的方法中 表示方法:{} 作用:控制变量的生命周期,减少内存消耗 demo: public class LocalCode { public static void main(String [] args){ int y = 10; { int x = 20; System.out.println(x); } System.out.println(y);//运行到此时x变量已被垃圾收集 } } 2.构造代码块 位置:位于类中 表示方法:{} 作用:用于给每个对象进行初…
多校10 1002 HDU 6172 Array Challenge 题意 There's an array that is generated by following rule. \(h_0=2,h_1=3,h_2=6,h_n=4h_{n-1}+17h_{n-2}-12h_{n-3}-16\) And let us define two arrays bnandan as below. $ b_n=3h_{n+1} h_n+9h_{n+1} h_{n-1}+9h_n^2+27h_n h_{n…
