Anton and Ira 我们把点分为三类, 向左走的, 向右走的, 不动的. 最完美的情况就是每个点没有走反方向. 每次我们挑选最右边的向右走的去把向左走的交换过来,这样能保证最优. #include<bits/stdc++.h> #define LL long long #define fi first #define se second #define mk make_pair #define PLL pair<LL, LL> #define PLI pair<LL,…

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: $p$:$5,1,\underline{2},\underline{3},4,6$ $s$:$…

题意简述: 给定一个$1$到$n(n<=2000)$的初始排列以及最终排列 我们每次可以选取位置为$i$和$j$的 并交换它们的位置 花费为$ |i-j| $ 求从初始状态变换到末状态所需最小花费 ----------------------------------------------------------------------------------------------------------- 比赛时这题留了$40min$ 然而自己贪心策略还是有漏洞 结束后看了首页的官方题解 感…

E. Anton and Ira Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/584/problem/E Description Anton loves transforming one permutation into another one by swapping elements for money, and Ira doesn't like paying for stupid game…

time limit per test1 second memory limit per test256 megabytes inputstandard input outputstandard output Anton loves transforming one permutation into another one by swapping elements for money, and Ira doesn't like paying for stupid games. Help them…

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}…