简单判断. 找第一类区间中$R$最大的,以及第二类区间中$L$最小的,判断距离. 找第二类区间中$R$最大的,以及第一类区间中$L$最小的,判断距离. 两种情况取个最大值即可. #include <cstdio> #include <cmath> #include <cstring> #include <map> #include <algorithm> using namespace std; int n,m; int a,b,c,d; int…

B. Anton and Classes 题目连接: http://codeforces.com/contest/785/problem/B Description Anton likes to play chess. Also he likes to do programming. No wonder that he decided to attend chess classes and programming classes. Anton has n variants when he wil…

Anton and Classes Anton likes to play chess. Also he likes to do programming. No wonder that he decided to attend chess classes and programming classes. Anton has n variants when he will attend chess classes, i-th variant is given by a period of time…

[题目链接]:http://codeforces.com/contest/785/problem/B [题意] 给你两个时间各自能够在哪些时间段去完成; 让你选择两个时间段来完成这两件事情; 要求两段时间的间隔最长(休息的时间最长) [题解] 考虑最后的答案; 只会是 (l,r).....(left,right) (left,right)...(l,r) else 这3种情况 对于第一种记录第一件事右端点的最小值,第二件事左端点的最大值; 对于第二种记录第二件事右端点的最小值,第一件事左端点的最…

E. Anton and Tree time limit per test: 3 seconds memory limit per test :256 megabytes input:standard input output: standard output Anton is growing a tree in his garden. In case you forgot, the tree is a connected acyclic undirected graph. There are …

LINK time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output The teacher gave Anton a large geometry homework, but he didn't do it (as usual) as he participated in a regular round on Codeforces. In…

[题目链接] http://codeforces.com/problemset/problem/734/F [题目大意] 给出数列b和数列c,求数列a,如果不存在则输出-1 [题解] 我们发现: bi+ci=2n*ai-(所有ai为1且aj为0的数位)+(ai为0且aj为1的数位)= n*ai+Σak 记为(1)式 同时又有(ai为1且aj为0的数位)+(aj为1且ai为0的数位)=ai xor aj 那么Σ(bi+ci)=Σ(2n*ai)-Σ(ai xor aj)+Σ(ai xor aj)=Σ…

Description As you probably know, Anton goes to school. One of the school subjects that Anton studies is Bracketology. On the Bracketology lessons students usually learn different sequences that consist of round brackets (characters "(" and &quo…

题目链接:https://codeforces.com/problemset/problem/785/D 题解: 首先很好想的,如果我们预处理出每个 "(" 的左边还有 $x$ 个 "(",以及右边有 $y$ 个 ")",那么就有式子如下: ① 若 $x+1 \le y$:$C_{x}^{0} C_{y}^{1} + C_{x}^{1} C_{y}^{2} + \cdots + C_{x}^{x} C_{y}^{x+1} = \sum_{i=0}…

题目链接:https://codeforces.com/contest/584/problem/E 题意: 给两个 $1 \sim n$ 的排列 $p,s$,交换 $p_i,p_j$ 两个元素需要花费 $|i-j|$,要求你用最少的钱交换 $p$ 中的元素使得其变成 $s$. 题解: 思路很简单,给个例子如下: $p$:$5,1,2,3,4,6$ $s$:$3,4,1,6,2,5$ 我们不难发现,像: $p$:$5,1,\underline{2},\underline{3},4,6$ $s$:$…