Codeforces Round #395 (Div. 2) D. Timofey and rectangles
地址:http://codeforces.com/contest/764/problem/D
题目:
2 seconds
256 megabytes
standard input
standard output
One of Timofey's birthday presents is a colourbook in a shape of an infinite plane. On the plane n rectangles with sides parallel to coordinate axes are situated. All sides of the rectangles have odd length. Rectangles cannot intersect, but they can touch each other.
Help Timofey to color his rectangles in 4 different colors in such a way that every two rectangles touching each other by side would have different color, or determine that it is impossible.
Two rectangles intersect if their intersection has positive area. Two rectangles touch by sides if there is a pair of sides such that their intersection has non-zero length
The picture corresponds to the first example
The first line contains single integer n (1 ≤ n ≤ 5·105) — the number of rectangles.
n lines follow. The i-th of these lines contains four integers x1, y1, x2 and y2 ( - 109 ≤ x1 < x2 ≤ 109, - 109 ≤ y1 < y2 ≤ 109), that means that points (x1, y1) and (x2, y2) are the coordinates of two opposite corners of the i-th rectangle.
It is guaranteed, that all sides of the rectangles have odd lengths and rectangles don't intersect each other.
Print "NO" in the only line if it is impossible to color the rectangles in 4 different colors in such a way that every two rectangles touching each other by side would have different color.
Otherwise, print "YES" in the first line. Then print n lines, in the i-th of them print single integer ci (1 ≤ ci ≤ 4) — the color of i-th rectangle.
8
0 0 5 3
2 -1 5 0
-3 -4 2 -1
-1 -1 2 0
-3 0 0 5
5 2 10 3
7 -3 10 2
4 -2 7 -1
YES
1
2
2
3
2
2
4
1
题意:给你n个边长都为奇数的长方形,问你能否使用四种颜色使所有相邻的长方形涂成不用颜色。
思路: 这题一定有解的,因为四色定理嘛,,然而比赛时想歪了,想先把长方形转化成图,相邻的长方形直接建一条无向边,然后用图的着色方法进行求解,这一点可以百度图的着色。
然而发现建图的时间复杂度太高,然后就GG了。。。。(其实可以扫描线建图,不过感觉太麻烦了)
做这题感觉智商被碾压了,其实这个题没有这么复杂。因为边长都为奇数,所以可以根据长方形的某一个顶点的坐标的奇偶进行染色。
以左下顶点为例,进行反证:
1.如果(a,b)与(c,d)涂了相同颜色,那么有a与c同奇偶,b与d同奇偶。(用长方形的左下顶点代表长方形)
2.因为长方形相邻,有 奇数(第一个长方形的顶点坐标x)+奇数(任意一个长方形的边长)=偶数(另一个长方形的对应顶点)
可以得出1与2相悖,所以假设不成立,其他情况同理可证。
所以按照长方形的某一个顶点的坐标的奇偶进行染色即可,,,感觉智商被碾压0.0
#include <bits/stdc++.h> using namespace std; #define MP make_pair
#define PB push_back
typedef long long LL;
typedef pair<int,int> PII;
const double eps=1e-;
const double pi=acos(-1.0);
const int K=1e6+;
const int mod=1e9+; int main(void)
{
int n;cin>>n;
printf("YES\n");
for(int i=,a,b,c,d,ans;i<=n;i++)
{
scanf("%d%d%d%d",&a,&b,&c,&d);
if(a&)
{
if(b&)
ans=;
else
ans=;
}
else
{
if(b&)
ans=;
else
ans=;
}
printf("%d\n",ans);
} return ;
}
Codeforces Round #395 (Div. 2) D. Timofey and rectangles的更多相关文章
- 【分类讨论】Codeforces Round #395 (Div. 2) D. Timofey and rectangles
D题: 题目思路:给你n个不想交的矩形并别边长为奇数(很有用)问你可以可以只用四种颜色给n个矩形染色使得相接触的 矩形的颜色不相同,我们首先考虑可不可能,我们分析下最多有几个矩形互相接触,两个时可以都 ...
- Codeforces Round #395 (Div. 2) C. Timofey and a tree
地址:http://codeforces.com/contest/764/problem/C 题目: C. Timofey and a tree time limit per test 2 secon ...
- Codeforces Round #395 (Div. 2)B. Timofey and cubes
地址:http://codeforces.com/contest/764/problem/B 题目: B. Timofey and cubes time limit per test 1 second ...
- 【树形DP】Codeforces Round #395 (Div. 2) C. Timofey and a tree
标题写的树形DP是瞎扯的. 先把1看作根. 预处理出f[i]表示以i为根的子树是什么颜色,如果是杂色的话,就是0. 然后从根节点开始转移,转移到某个子节点时,如果其子节点都是纯色,并且它上面的那一坨结 ...
- Codeforces Round #395 (Div. 2)(未完)
2.2.2017 9:35~11:35 A - Taymyr is calling you 直接模拟 #include <iostream> #include <cstdio> ...
- Codeforces Round #395 (Div. 2)
今天自己模拟了一套题,只写出两道来,第三道时间到了过了几分钟才写出来,啊,太菜了. A. Taymyr is calling you 水题,问你在z范围内 两个序列 n,2*n,3*n...... ...
- Codeforces Round #395 (Div. 2)(A.思维,B,水)
A. Taymyr is calling you time limit per test:1 second memory limit per test:256 megabytes input:stan ...
- Codeforces Round #395 (Div. 2) D
Description One of Timofey's birthday presents is a colourbook in a shape of an infinite plane. On t ...
- Codeforces Round #395 (Div. 2) B
Description Young Timofey has a birthday today! He got kit of n cubes as a birthday present from his ...
随机推荐
- Java技术学习路线图
一:常见模式与工具 学习Java技术体系,设计模式,流行的框架与组件是必不可少的: 常见的设计模式,编码必备 Spring5,做应用必不可少的最新框架 MyBatis,玩数据库必不可少的组件 二:工程 ...
- 如何用redis/memcache做Mysql缓存层
方法一:直接用MysqlMysql有缓存,实现了类似的功能,如果需要缓存的东西很多,可以把缓存的内存设置大一点.这样的好处就是不用去控制缓存的失效,确保数据一致性. 方法二:启用用DAO框架的缓存比如 ...
- spark(1.1) mllib 源码分析(三)-朴素贝叶斯
原创文章,转载请注明: 转载自http://www.cnblogs.com/tovin/p/4042467.html 本文主要以mllib 1.1版本为基础,分析朴素贝叶斯的基本原理与源码 一.基本原 ...
- poj 2386:Lake Counting(简单DFS深搜)
Lake Counting Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 18201 Accepted: 9192 De ...
- Eclipse下导入外部jar包的3种方式
http://blog.csdn.net/mazhaojuan/article/details/21403717
- poj3243 Clever Y[扩展BSGS]
Clever Y Time Limit: 5000MS Memory Limit: 65536K Total Submissions: 8666 Accepted: 2155 Descript ...
- iOS 如何在一个应用程序中调用另一个应用程序
原则上iOS的沙箱原理,是阻止一个app去访问其他app的资源乃至是系统底层的资源的但是我们可以通过一种变相的方式:通过对应的URL模式和其他程序进行通讯. iOS应用之间的调用步骤: 一, 调用自己 ...
- 慎用System.Web.HttpContext.Current
每当控制流离开页面派生的Web表单上的代码的时候,HttpContext类的静态属性Current可能是有用的. 使用这个属性,我们可以获取当前请求(Request),响应(Response),会话( ...
- CListCtrl消息及解释
对于CListCtrl消息的解释:[来自网络]LVN_BEGINDRAG 鼠标左键正在被触发以便进行拖放操作(当鼠标左键开始拖拽列表视图控件中的项目时产生) LVN_BEGINRDRAG 鼠标右键正在 ...
- 动态长度中英字符串显示至固定高度td
w 为td中英字符串区域设置为display:block; height=td_height,并指明td width. <!doctype html> <html lang=&quo ...