Codeforces Round #449 (Div. 2) C. DFS
2 seconds
256 megabytes
standard input
standard output

Nephren is playing a game with little leprechauns.
She gives them an infinite array of strings, f0... ∞.
f0 is "What are you doing at the end of the world? Are you busy? Will you save us?".
She wants to let more people know about it, so she defines fi = "What are you doing while sending "fi - 1"? Are you busy? Will you send "fi - 1"?" for all i ≥ 1.
For example, f1 is
"What are you doing while sending "What are you doing at the end of the world? Are you busy? Will you save us?"? Are you busy? Will you send "What are you doing at the end of the world? Are you busy? Will you save us?"?". Note that the quotes in the very beginning and in the very end are for clarity and are not a part of f1.
It can be seen that the characters in fi are letters, question marks, (possibly) quotation marks and spaces.
Nephren will ask the little leprechauns q times. Each time she will let them find the k-th character of fn. The characters are indexed starting from 1. If fn consists of less than k characters, output '.' (without quotes).
Can you answer her queries?
The first line contains one integer q (1 ≤ q ≤ 10) — the number of Nephren's questions.
Each of the next q lines describes Nephren's question and contains two integers n and k (0 ≤ n ≤ 105, 1 ≤ k ≤ 1018).
One line containing q characters. The i-th character in it should be the answer for the i-th query.
3
1 1
1 2
1 111111111111
Wh.
5
0 69
1 194
1 139
0 47
1 66
abdef
10
4 1825
3 75
3 530
4 1829
4 1651
3 187
4 584
4 255
4 774
2 474
Areyoubusy
For the first two examples, refer to f0 and f1 given in the legend.
思路: 字符串长度的递推式:f[n]=2*f[n-1]+l1+l2+l3,然后分成5段来找所求字母,l1-(s[n-1])-l2-(s[n-1])-l3.
代码:
#include<bits/stdc++.h>
#define db double
#define ll long long
#define vec vector<ll>
#define Mt vector<vec>
#define ci(x) scanf("%d",&x)
#define cd(x) scanf("%lf",&x)
#define cl(x) scanf("%lld",&x)
#define pi(x) printf("%d\n",x)
#define pd(x) printf("%f\n",x)
#define pl(x) printf("%lld\n",x)
//#define rep(i, x, y) for(int i=x;i<=y;i++)
const int N = 1e6 + ;
const int mod = 1e9 + ;
const int MOD = mod - ;
const db eps = 1e-;
const db PI = acos(-1.0);
using namespace std;
string s0="What are you doing at the end of the world? Are you busy? Will you save us?",
s1="What are you doing while sending \"",s2="\"? Are you busy? Will you send \"",s3="\"?"; ll f[N]={,,,,};
int l1,l2,l3;
void init()
{
for(int i=;;i++){
ll x=f[i-]*+;
if(x>1e18) break;
f[i]=f[i-]*+;
}
}
char dfs(ll n,ll k)
{
if(!n) return k<=?s0[k-]:'.';
if(k<=l1) return s1[k-];//第一段
k-=l1;
if(k<=f[n-]||!f[n-]) return dfs(n-,k);//在范围内或者当前字符串长度远超目标位置
k-=f[n-];
if(k<=l2) return s2[k-];//s2的范围内
k-=l2;
if(k<=f[n-]||!f[n-]) return dfs(n-,k);
k-=f[n-];
return k<=l3?s3[k-]:'.';//最后一段 }
int main(){
init();
ll n,k;
int t;
ci(t);
l1=(int)s1.size(),l2=(int)s2.size(),l3=(int)s3.size();
while(t--)
{
cl(n),cl(k);
putchar(dfs(n,k));
}
return ;
}
Codeforces Round #449 (Div. 2) C. DFS的更多相关文章
- Codeforces Round #449 (Div. 2)
Codeforces Round #449 (Div. 2) https://codeforces.com/contest/897 A #include<bits/stdc++.h> us ...
- Codeforces Round #449 (Div. 2)ABCD
又掉分了0 0. A. Scarborough Fair time limit per test 2 seconds memory limit per test 256 megabytes input ...
- Codeforces Round #381 (Div. 2) D dfs序+树状数组
D. Alyona and a tree time limit per test 2 seconds memory limit per test 256 megabytes input standar ...
- Codeforces Codeforces Round #383 (Div. 2) E (DFS染色)
题目链接:http://codeforces.com/contest/742/problem/E 题意: 有一个环形的桌子,一共有n对情侣,2n个人,一共有两种菜. 现在让你输出一种方案,满足以下要求 ...
- Codeforces Round #290 (Div. 2) B (dfs)
题目链接:http://codeforces.com/problemset/problem/510/B 题意:判断图中是否有某个字母成环 思路:直接dfs就好了,注意判断条件:若下一个字母与当前字母相 ...
- Codeforces Round #222 (Div. 1) Maze —— dfs(连通块)
题目链接:http://codeforces.com/problemset/problem/377/A 题解: 有tot个空格(输入时统计),把其中k个空格变为wall,问怎么变才能使得剩下的空格依然 ...
- Codeforces Round #428 (Div. 2) C. dfs
C. Journey time limit per test 2 seconds memory limit per test 256 megabytes input standard input ou ...
- Codeforces Round #321 (Div. 2) C dfs处理(双向边叶子节点的判断)
C. Kefa and Park time limit per test 2 seconds memory limit per test 256 megabytes input standard in ...
- Codeforces Round #449 (Div. 2) B. Chtholly's request【偶数位回文数】
B. Chtholly's request time limit per test 2 seconds memory limit per test 256 megabytes input standa ...
随机推荐
- 《java提高数据导入效率优化思路》
写在前边的实现需求: 1.总共10万个电话号码: 2.电话号码中有重复和错误: 3.查找出正确的号码(不重复): 一.优化前的实现方式: 1.先用正则过滤一遍10万条数据,找出错误的: 2.用List ...
- LeeCode 第1题
要求: 给定一个整数(int)数组(Array)和一个目标数值(Target),找出数组中两数之和等于目标值(target)的两个元素的下标位置, 假设:结果唯一,数组中元素不会重复. 本人思路:分别 ...
- java:xml解析
DOM.SAX.JDOM.DOM4J四种解析:https://www.cnblogs.com/longqingyang/p/5577937.html Java解析XML文件例子:https://blo ...
- strdup和strndup函数
首先说明一下:这两个函数不建议使用,原因是返回内存地址把释放权交给别的变量,容易忘记释放. 一.strdup函数 函数原型 头文件:#include <string.h> char *st ...
- [topcoder]TheConsecutiveIntegersDivOne
http://community.topcoder.com/stat?c=problem_statement&pm=13625&rd=16278 首先,如果记得曼哈顿距离最小值那个问题 ...
- Django Field lookups (字段查找)
字段查找是指定SQL WHERE子句的核心内容的方式. 它们被指定为QuerySet方法filter().exclude()和get()的关键字参数. 1.exact:精确查找.如果为比较提供的值为N ...
- NO.003-2018.02.08《江城子·乙卯正月二十日夜记梦》宋代:苏轼
江城子·乙卯正月二十日夜记梦_古诗文网 江城子·乙卯正月二十日夜记梦 乙卯:公元1075年,即北宋熙宁八年. 宋代:苏轼 十年生死两茫茫,不思量,自难忘.千里孤坟,无处话凄凉.纵使相逢应不识,尘满面, ...
- Xcode SDK模拟器安装及安装路径
将SDK想要装的版本,将SDK包放入‘mac中的SDK安装路径’.再将Xcode模拟器重启. 再打开Xcode模拟器,就可以在菜单栏的 ‘硬件’->’设备‘->’iPhone Retina ...
- 在IDEA中创建Maven项目和添加tomcat
IDEA中创建是一种创建maven项目的办法,但不推荐,因为没有使用统一的骨架,可以一开始就选择创建maven项目,步骤如下: 第一步 第二步:设置项目 第三步:进行配置好maven,加上 arche ...
- 开发者不容错过的10款免费JavaScript游戏引擎
摘要:使用HTML5.JavaScript可以帮助开发者开发出各种与众不同的游戏及游戏特效,比如3D动画.Canvas等.本文介绍10款被广泛使用的基于HTML5的JavaScript游戏引擎. 在G ...