codeforces 508B
2 seconds
256 megabytes
standard input
standard output
User ainta has a permutation p1, p2, ..., pn. As the New Year is coming, he wants to make his permutation as pretty as possible.
Permutation a1, a2, ..., an is prettier than permutation b1, b2, ..., bn, if and only if there exists an integer k (1 ≤ k ≤ n) where a1 = b1, a2 = b2, ..., ak - 1 = bk - 1 and ak < bk all holds.
As known, permutation p is so sensitive that it could be only modified by swapping two distinct elements. But swapping two elements is harder than you think. Given an n × n binary matrix A, user ainta can swap the values of pi and pj (1 ≤ i, j ≤ n, i ≠ j) if and only if Ai, j = 1.
Given the permutation p and the matrix A, user ainta wants to know the prettiest permutation that he can obtain.
The first line contains an integer n (1 ≤ n ≤ 300) — the size of the permutation p.
The second line contains n space-separated integers p1, p2, ..., pn — the permutation p that user ainta has. Each integer between 1 and n occurs exactly once in the given permutation.
Next n lines describe the matrix A. The i-th line contains n characters '0' or '1' and describes the i-th row of A. The j-th character of the i-th line Ai, j is the element on the intersection of the i-th row and the j-th column of A. It is guaranteed that, for all integers i, j where 1 ≤ i < j ≤ n, Ai, j = Aj, i holds. Also, for all integers i where 1 ≤ i ≤ n, Ai, i = 0 holds.
In the first and only line, print n space-separated integers, describing the prettiest permutation that can be obtained.
75 2 4 3 6 7 10001001000000000000101000001000000000100001001000
1 2 4 3 6 7 5
54 2 1 5 30010000011100100110101010
1 2 3 4 5
In the first sample, the swap needed to obtain the prettiest permutation is: (p1, p7).
In the second sample, the swaps needed to obtain the prettiest permutation is (p1, p3), (p4, p5), (p3, p4).

A permutation p is a sequence of integers p1, p2, ..., pn, consisting of n distinct positive integers, each of them doesn't exceed n. The i-th element of the permutation p is denoted as pi. The size of the permutation p is denoted as n.
题意:给你一个数字n,然后底下n个数字,然后再给你n排01串,01串的意思是如果第i行第j列的数字是1,那么上面的数字串里的第i个数字和第j个数字就可以交换位置,题目保证m[i][j] = m[j][i],问你按照这么操作下来(如果m[i][j] = 1,那么A[i]与A[j]可交换,也可不交换),能得到的数字串最小的字典序是多少
思路:dfs
#include <iostream>
using namespace std;
int m[400][400];
int g[400];
bool vis[400];
int x;
int t,it;
bool flag[400];
int w[400];
//dfs的目的是得到x可以的最小值
void dfs( int a ){
if( !vis[g[a]] ){//如果说g[a]没有遍历过,那么取小的值
x = min( x,g[a] );
}
w[a] = it;//然后第a个数字,就用过了,防止下面出现死循环
for( int i = 0; i < t; i++ ){
if( m[a][i] == 1 and w[i] != it ){//搜索可能出现的最小值
dfs(i);
}
}
}
int main(){
cin >> t;
for( int i = 0; i < t; i++ ){
scanf("%d",&g[i]);
}
for( int i = 0; i < t; i++ ){
for( int j = 0; j < t; j++ ){
scanf("%1d",&m[i][j]);
}
}
for( int i = 0; i < t; i++ ){
it++;//记录是第几个数字
x = t;//先令x的序号为最大
dfs(i);
vis[x] = true;
printf("%d ",x);
}
}
好多大佬用的是floyd算法,仔细研究了一下dalao的代码,受益匪浅啊~
#include <iostream>
using namespace std;
const int maxn = 400;
bool vis[maxn];
int A[maxn],m[maxn][maxn];
int a;
int pos[maxn];
int main(){
cin >> a;
for( int i = 1; i <= a; i++ ){
cin >> A[i];
pos[A[i]] = i;//离散化,这不操作可以即可以根据数字找到位置,也可以根据位置找到数字
}
for( int i = 1; i <= a; i++ ){
for( int j = 1; j <= a; j++ ){
scanf("%1d",&m[i][j]);
}
m[i][i] = 1;//自己与自己交换是被允许的
}
for( int k = 1; k <= a; k++ ){// floyd一下
for( int i = 1; i <= a; i++ ){
for( int j = 1; j <= a; j++ ){
if( m[i][k] == 1 and m[k][j] == 1 ){
m[i][j] = 1;
}
}
}
}
//i代表i号位置,j代表数字j
for( int i = 1; i <= a; i++ ){//这个循环是循环数组
for( int j = 1; j <= a; j++ ){
if( m[i][pos[j]] == 1 and !vis[j] ){//因为pos[j]是j的位置,j又是从小到达的,这步贪心
cout << j << " ";
vis[j] = true;//j这个数字用过了
pos[A[i]] = pos[j];//改变A[i]的位置为j的位置(A[i]与j位置互换)
pos[j] = i;//j的位置变成了i
break;
}
}
}
}
codeforces 508B的更多相关文章
- 【codeforces 508B】Anton and currency you all know
[题目链接]:http://codeforces.com/contest/508/problem/B [题意] 给你一个奇数; 让你交换一次数字; 使得这个数字变成偶数; 要求偶数要最大; [题解] ...
- python爬虫学习(5) —— 扒一下codeforces题面
上一次我们拿学校的URP做了个小小的demo.... 其实我们还可以把每个学生的证件照爬下来做成一个证件照校花校草评比 另外也可以写一个物理实验自动选课... 但是出于多种原因,,还是绕开这些敏感话题 ...
- 【Codeforces 738D】Sea Battle(贪心)
http://codeforces.com/contest/738/problem/D Galya is playing one-dimensional Sea Battle on a 1 × n g ...
- 【Codeforces 738C】Road to Cinema
http://codeforces.com/contest/738/problem/C Vasya is currently at a car rental service, and he wants ...
- 【Codeforces 738A】Interview with Oleg
http://codeforces.com/contest/738/problem/A Polycarp has interviewed Oleg and has written the interv ...
- CodeForces - 662A Gambling Nim
http://codeforces.com/problemset/problem/662/A 题目大意: 给定n(n <= 500000)张卡片,每张卡片的两个面都写有数字,每个面都有0.5的概 ...
- CodeForces - 274B Zero Tree
http://codeforces.com/problemset/problem/274/B 题目大意: 给定你一颗树,每个点上有权值. 现在你每次取出这颗树的一颗子树(即点集和边集均是原图的子集的连 ...
- CodeForces - 261B Maxim and Restaurant
http://codeforces.com/problemset/problem/261/B 题目大意:给定n个数a1-an(n<=50,ai<=50),随机打乱后,记Si=a1+a2+a ...
- CodeForces - 696B Puzzles
http://codeforces.com/problemset/problem/696/B 题目大意: 这是一颗有n个点的树,你从根开始游走,每当你第一次到达一个点时,把这个点的权记为(你已经到过不 ...
随机推荐
- import 搜索路径
来源 http://www.runoob.com/python/python-mysql.html 搜索路径 当你导入一个模块,Python 解析器对模块位置的搜索顺序是: 1.当前目录 2.如果不在 ...
- RabbitMQ--windows10环境下的RabbitMQ安装步骤(转)
https://blog.csdn.net/weixin_39735923/article/details/79288578
- centos7 下通过yum安装JDK
1.查看yum库中jdk的版本 2.下载安装的jdk 3.会出现几个选择 Is this ok . 输入 y 就可以了. 4.配置环境变量 vi /etc/profile 进入编辑文本在最 ...
- java中将表单转换为PDF
经过网上搜索大概有三种方式:PDF模板数据填充,html代码转换pdf,借用wkhtmltopdf工具 一 .PDF模板数据填充 1.新建word,在word中做出和表单一样的布局的空表单,然后另存为 ...
- [UnityShader基础]03.透明度混合
如果要渲染半透明物体,那么就需要用到透明度混合. 需要注意的有这几点: 1.设置标签:Tags { "Queue"="Transparent" "Ig ...
- IntelliJ IDEA 导入多个maven项目
IntelliJ IDEA的功能十分强大 我们日常开发项目会分多个maven项目 idea单个打开切换很是麻烦 下边是idea可以同时导入多个项目的方法 1.选择 FIle -> NEW -& ...
- SecureCR 改变背景色和文字颜色
1.打开SecureCR链接Linux服务器,Options->Session Options->Emulation->Terminal 选择Linux (相应的服务器系统)ANSI ...
- 总结http状态码和200,304状态码
状态码 响应类别 中文意思 1XX 信息性状态码(Informational) 服务器正在处理请求 2XX 成功状态码(Success) 请求已正常处理完毕 3XX 重定向状态码(Redirec ...
- 使用jQuery+huandlebars循环遍历中使用索引
兼容ie8(很实用,复制过来,仅供技术参考,更详细内容请看源地址:http://www.cnblogs.com/iyangyuan/archive/2013/12/12/3471227.html) & ...
- quick pdf library控件
quick pdf library库只能在windows环境下运行 1.下载quick pdf library 2.注册控件 进入cmd regsvr32 "C:\Program File ...