Codeforces Round #394 (Div. 2) D. Dasha and Very Difficult Problem —— 贪心
题目链接:http://codeforces.com/contest/761/problem/D
2 seconds
256 megabytes
standard input
standard output
Dasha logged into the system and began to solve problems. One of them is as follows:
Given two sequences a and b of
length n each you need to write a sequence c of
length n, the i-th
element of which is calculated as follows: ci = bi - ai.
About sequences a and b we
know that their elements are in the range from l to r.
More formally, elements satisfy the following conditions: l ≤ ai ≤ r and l ≤ bi ≤ r.
About sequence c we know that all its elements are distinct.

Dasha wrote a solution to that problem quickly, but checking her work on the standard test was not so easy. Due to an error in the test system only the sequence a and
the compressed sequence of the sequence c were known from that test.
Let's give the definition to a compressed sequence. A compressed sequence of sequence c of
length n is a sequence p of
length n, so that pi equals
to the number of integers which are less than or equal to ci in
the sequence c. For example, for the sequence c = [250, 200, 300, 100, 50] the
compressed sequence will be p = [4, 3, 5, 2, 1]. Pay attention that in c all
integers are distinct. Consequently, the compressed sequence contains all integers from 1 to n inclusively.
Help Dasha to find any sequence b for which the calculated compressed sequence of
sequence c is correct.
The first line contains three integers n, l, r (1 ≤ n ≤ 105, 1 ≤ l ≤ r ≤ 109) —
the length of the sequence and boundaries of the segment where the elements of sequences a and b are.
The next line contains n integers a1, a2, ..., an (l ≤ ai ≤ r) —
the elements of the sequence a.
The next line contains n distinct integers p1, p2, ..., pn (1 ≤ pi ≤ n) —
the compressed sequence of the sequence c.
If there is no the suitable sequence b, then in the only line print "-1".
Otherwise, in the only line print n integers — the elements of any suitable sequence b.
5 1 5
1 1 1 1 1
3 1 5 4 2
3 1 5 4 2
4 2 9
3 4 8 9
3 2 1 4
2 2 2 9
6 1 5
1 1 1 1 1 1
2 3 5 4 1 6
-1
Sequence b which was found in the second sample is suitable, because calculated sequence c = [2 - 3, 2 - 4, 2 - 8, 9 - 9] = [ - 1, - 2, - 6, 0] (note
that ci = bi - ai)
has compressed sequence equals to p = [3, 2, 1, 4].
题解:
1.首先将a数组按照p数组排序,然后按照p数组从小到大开始推出b数组。由于p数组是递增的,所以每获得一个b[i],p可取的最小值就会增加。
2.为了之后p的取值范围尽可能大,当前的p应该取范围内的最小值。
3.p合适的最小值推导:
假设当前p的最小值为minn, 则:minn<=p<=r-a。
而因为b = p+a, l<=b<=r,所以:l-a<=p<=r-a。
所以p合适的最小值 = max(minn, l-a)。
代码如下:
#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
const double eps = 1e-6;
const int INF = 2e9;
const LL LNF = 9e18;
const int mod = 1e9+7;
const int maxn = 1e5+10; int A[maxn], a[maxn], b[maxn], p[maxn];
int n, l, r; void init()
{
scanf("%d%d%d",&n,&l,&r);
for(int i = 1; i<=n; i++)
scanf("%d",&A[i]);
for(int i = 1; i<=n; i++)
{
scanf("%d",&p[i]);
a[p[i]] = A[i];
}
} void solve()
{
int minn = -INF;
for(int i = 1; i<=n; i++)
{
b[i] = max(minn, l-a[i])+a[i]; // b = p合适的最小值 + a
minn = max(minn, l-a[i])+1; //p数组严格递增
if(b[i]<l || b[i]>r)
{
puts("-1");
return;
}
} for(int i = 1; i<=n; i++)
printf("%d ",b[p[i]]);
} int main()
{
init();
solve();
}
Codeforces Round #394 (Div. 2) D. Dasha and Very Difficult Problem —— 贪心的更多相关文章
- Codeforces Round #394 (Div. 2) D. Dasha and Very Difficult Problem 贪心
D. Dasha and Very Difficult Problem 题目连接: http://codeforces.com/contest/761/problem/D Description Da ...
- Codeforces Round #394 (Div. 2) D. Dasha and Very Difficult Problem
D. Dasha and Very Difficult Problem time limit per test:2 seconds memory limit per test:256 megabyte ...
- Codeforces Round #394 (Div. 2) E. Dasha and Puzzle(分形)
E. Dasha and Puzzle time limit per test 2 seconds memory limit per test 256 megabytes input standard ...
- Codeforces Round #394 (Div. 2) E. Dasha and Puzzle 构造
E. Dasha and Puzzle 题目连接: http://codeforces.com/contest/761/problem/E Description Dasha decided to h ...
- Codeforces Round #394 (Div. 2) C. Dasha and Password 暴力
C. Dasha and Password 题目连接: http://codeforces.com/contest/761/problem/C Description After overcoming ...
- Codeforces Round #394 (Div. 2) B. Dasha and friends 暴力
B. Dasha and friends 题目连接: http://codeforces.com/contest/761/problem/B Description Running with barr ...
- Codeforces Round #394 (Div. 2) A. Dasha and Stairs 水题
A. Dasha and Stairs 题目连接: http://codeforces.com/contest/761/problem/A Description On her way to prog ...
- Codeforces Round #394 (Div. 2) C. Dasha and Password —— 枚举
题目链接:http://codeforces.com/problemset/problem/761/C C. Dasha and Password time limit per test 2 seco ...
- Codeforces Round #394 (Div. 2) B. Dasha and friends —— 暴力 or 最小表示法
题目链接:http://codeforces.com/contest/761/problem/B B. Dasha and friends time limit per test 2 seconds ...
随机推荐
- 树讲解——牧场行走( lca )
大视野 1602: [Usaco2008 Oct]牧场行走 Time Limit: 5 Sec Memory Limit: 64 MBSubmit: 1947 Solved: 1021[Sub ...
- Codeforces A. Bear and Big Brother
...不行.这题之后.不做1000分以下的了.很耻辱 A. Bear and Big Brother time limit per test 1 second memory limit per t ...
- 设计模式之状态模式(State)摘录
23种GOF设计模式一般分为三大类:创建型模式.结构型模式.行为模式. 创建型模式抽象了实例化过程,它们帮助一个系统独立于怎样创建.组合和表示它的那些对象.一个类创建型模式使用继承改变被实例化的类,而 ...
- svn hooks 实现自动更新
搞来搞去,原来是hooks 下面的脚本名称必须是post-commit才可以, 写成fly-commit一直不行.晕死~~~ https://serverfault.com/questions/144 ...
- C#中toolStrip或statusStrip遮挡了SplitContainer怎么办?
如果在一个项目中先增添了SplitContainer,然后再添加的Toolbar或statusStrip,结果后者把前者上部或下部挡住了一条,造成界面别扭. 解决办法是右键点击Toolba或statu ...
- 网站无法显示logo?
那是因为你没有配置favicon.ico,每个网站根目录都会有一个favicon.ico,因为每个服务器都会请求根目录下的它.
- python(31)- 模块练习
1. 小程序:根据用户输入选择可以完成以下功能: 创意文件,如果路径不存在,创建文件夹后再创建文件 能够查看当前路径 在当前目录及其所有子目录下查找文件名包含指定字符串的文件 ...
- python(33)- 模块与包
一 模块 1 什么是模块? 一个模块就是一个包含了python定义和声明的文件,文件名就是模块名字加上.py的后缀. 2 为何要使用模块? 如果你退出python解释器然后重新进入,那么你之前定义的函 ...
- selenium之 文件上传方法
文件上传是所有UI自动化测试都要面对的一个头疼问题 首先,我们要区分出上传按钮的种类,大体上可以分为两种,一种是input框,另外一种就比较复杂,通过js.flash等实现,标签非input 我们分别 ...
- linux之return和exit引发的大问题(vfork和fork)
在coolshell.cn上看到的一个问题.为此拿来研究一下. 首先 看看return和exit的差别 在linux上分别跑一下这个代码 int main() { return 0; //exit(0 ...