어제 밤 12시에 열린 매치..
옐로우 달성이 후 첫번째 매치였는데..
근래 보기드문 졸전끝에 한문제도 못풀고 레이팅도 100점 이상 떨어졌다.. 젠장.. ㅠ_ㅠ
더욱이 어이가없는건 다른사람 다 푼 문제를 나만 못풀었다..
250점짜리 문제를 그냥 싸이클 개수만 구하면 된다는데..
왜 그게 답이되는지.. 여전히 아리송하다..
어제 매치에서 특이한점은.. 매치시작 한시간전에 등록을 하려고하는데..
1750명이 이미 마감되었다.. (원래는 등록마감시까지도 1750명이 다 차는경우가 거의 없는데..)
그래서 등록못한 사람들의 원성이 자자하자 결국 limit을 2000까지 늘렸다..
그러나 그마저도 5분도 안되서 다 차버렸다.. ㅋㅋ
왜케 사람이 많나 봤더니.. 다 중국애들.. -_-;; 그것도 처음 시작하는애들이 700명이나됐다..
덕분에 시작 몇분전에 아레나 뻗어버리고.. 우여곡절끝에 15분 늦게 시작됐다..
탑코더도 툭하면 뻗어버리고.. 이제 서버좀 업그레이드해라..
[250] PerfectPermutation
Problem Statement
A permutation A[0], A[1], ..., A[N-1] is a sequence containing each integer between 0 and N-1, inclusive, exactly once. Each permutation A of length N has a corresponding child array B of the same length, where B is defined as follows:
B[0] = 0
B[i] = A[B[i-1]], for every i between 1 and N-1, inclusive.
A permutation is considered perfect if its child array is also a permutation. Below are given all permutations for N=3 with their child arrays. Note that for two of these permutations ({1, 2, 0} and {2, 0, 1}) the child array is also a permutation, so these two permutations are perfect.
Permutation Child array
{0, 1, 2} {0, 0, 0}
{0, 2, 1} {0, 0, 0}
{1, 0, 2} {0, 1, 0}
{1, 2, 0} {0, 1, 2}
{2, 0, 1} {0, 2, 1}
{2, 1, 0} {0, 2, 0}
You are given a vector <int> P containing a permutation of length N. Find a perfect permutation Q of the same length such that the difference between P and Q is as small as possible, and return this difference. The difference between P and Q is the number of indices i for which P[i] and Q[i] are different.
Definition
Class:
PerfectPermutation
Method:
reorder
Parameters:
vector <int>
Returns:
int
Method signature:
int reorder(vector <int> P)
(be sure your method is public)
Constraints
-
P will contain between 1 and 50 elements, inclusive.
-
P will contain each integer between 0 and N-1, inclusive, exactly once, where N is the number of elements in P.
Examples
0)
{2, 0, 1}
Returns: 0
P is a perfect permutation, so we can use the same permutation for Q. The difference is then 0 because P and Q are the same.
1)
This problem statement is the exclusive and proprietary property of TopCoder, Inc. Any unauthorized use or reproduction of this information without the prior written consent of TopCoder, Inc. is strictly prohibited. (c)2003, TopCoder, Inc. All rights reserved.
0...n-1의 permutation A[n] 이 주어지고.. B는 다음과 같다..
B[0] = 0
B[i] = A[B[i-1]]
이때 B[n] 이 A[n]의 permutation이면 A를 perfect permutation 이라고 한다..
이때 input P[n] 에 대해서 가장 가까운 perfect permutation Q[n]를 구하기..
가깝다는 의미는 count(P[i] <> Q[i]) {i = 0..n-1} 을 의미한다..
아.. 이글을 보고 내가 문제를 잘못이해하고 있었다는걸 알았다..
나는 sum{abs(P[i] - Q[i])} {i = 0...n-1} 을 minimize 하라는줄 알고 삽질했는데..
문제는 전혀 엉뚱한 내용이었다.. ㅠ_ㅠ 어쩐지 다들 잘 풀더라.. ㅋㅋ
에디토리얼 생략
[500] StrangeCountry
Problem Statement
There is a country with N cities, some of which are connected with bidirectional roads. Your task is to reconfigure the roads so that it is possible to get from each city to every other city. You must do this using the minimum possible number of transformations, where each transformation consists of the following steps:
Choose four different cities A, B, C and D, where roads (A, B) and (C, D) exist, but (A, C), (A, D), (B, C) and (B, D) do not exist.
Destroy roads (A, B) and (C, D).
Build two new roads - either (A, C) and (B, D), or (A, D) and (B, C).
The following images show an example of this transformation. From the first situation you can get the second one or the third one:
You are given a vector <string> g, where the j-th character of the i-th element is 'Y' if there is a road between cities i and j, and 'N' otherwise. Return minimal number of transformations required to accomplish your task, or return -1 if it is impossible.
Definition
Class:
StrangeCountry
Method:
transform
Parameters:
vector <string>
Returns:
int
Method signature:
int transform(vector <string> g)
(be sure your method is public)
Constraints
-
g will contain between 2 and 50 elements, inclusive.
-
Each element of g will contain exactly N characters 'Y' or 'N', where N is the number of elements in g.
-
For each i and j, g[i][j] will be equal to g[j][i].
-
For each i, g[i][i] will be equal to 'N'.
Examples
0)
{"NY",
"YN"}
Returns: 0
This country is already connected.
1)
This problem statement is the exclusive and proprietary property of TopCoder, Inc. Any unauthorized use or reproduction of this information without the prior written consent of TopCoder, Inc. is strictly prohibited. (c)2003, TopCoder, Inc. All rights reserved.
to be updated..
[1000] PaperAndPaint
Problem Statement
Onise likes to play with paper and paint. He has a piece of paper with dimensions width x height. He performs K operations, one for each i between 0 and K-1, inclusive. Each operation consists of the following steps:
Fold the paper along the line x = xfold[i] (the left side of the paper is folded over the right side).
Divide the paper vertically into cnt[i]+1 equal sections. Then, cnt[i] times, take the topmost section and fold it over the section below it.
Paint a rectangle with the lower-left corner at (x1[i], y1[i]) and the upper-right corner at (x2[i], y2[i]). Note that (0, 0) is now the lower-left corner of the paper in its current folded state, not its original state. The paint will seep through all the layers of the folded paper. See the image below for clarification.
Unfold the paper.
For example, let's say Onise has a piece of paper that is 5 x 6. He performs one operation where xfold is 2, cnt is 2, and the coordinates of the painted rectangle's corners are (1, 1) and (3, 2). The following will happen (note that the paper starts out blue in the images and gets painted white):
You are given ints width and height, and int[]s xfold, cnt, x1, y1, x2 and y2, each containing exactly K elements. Return the total area of of the paper that is not covered in paint after Onise is done.
Definition
Class:
PaperAndPaint
Method:
computeArea
Parameters:
int, int, int[], int[], int[], int[], int[], int[]
Returns:
long
Method signature:
long computeArea(int width, int height, int[] xfold, int[] cnt, int[] x1, int[] y1, int[] x2, int[] y2)
(be sure your method is public)
Constraints
-
width and height will be between 1 and 10^9, inclusive.
-
xfold, cnt, x1, y1, x2 and y2 will all contain the same number of elements, between 1 and 50, inclusive.
-
Every element of xfold will be between 0 and width, inclusive.
-
Every element of cnt will be between 0 and 1000, inclusive.
-
For every i, cnt[i]+1 will be a divisor of height.
-
For every i, 0 <= x1[i] < x2[i] <= max(xfold[i], width-xfold[i]) and 0 <= y1[i] < y2[i] <= height/(cnt[i]+1).
Examples
0)
5
6
{2}
{2}
{1}
{1}
{3}
{2}
Returns: 21
The example from the problem statement.
1)
2
4
{0, 0}
{1, 0}
{0, 0}
{1, 1}
{2, 1}
{2, 4}
Returns: 3
Onise will get the following result:
2)
This problem statement is the exclusive and proprietary property of TopCoder, Inc. Any unauthorized use or reproduction of this information without the prior written consent of TopCoder, Inc. is strictly prohibited. (c)2003, TopCoder, Inc. All rights reserved.
