Programming contests

Magas szintű programozási nyelvek 1, egyéni verseny, 2015. április 12.

April 12, 2015 10:00 AM – April 12, 2015 3:00 PM

Ants

An army of ants walk on a horizontal pole of length l cm, each with a constant speed of 1 cm/s. When a walking ant reaches an end of the pole, it immediately falls off it. When two ants meet, they turn back and start walking in opposite directions. We know the original positions of ants on the pole, but unfortunately, we do not know the directions in which the ants are walking. Your task is to compute the earliest and the latest possible times needed for all ants to fall off the pole.

Input Specification

The first line of the input contains one integer giving the number of test cases that follow. The data for each case start with two integer numbers: the length of the pole (in cm) and n, the number of ants residing on the pole. These two numbers are followed by n integers giving the position of each ant on the pole as the distance measured from the left end of the pole, in no particular order. All input integers are not bigger than 1 000 000, and they are separated by whitespace.

Output Specification

For each case of input, output two numbers in a separate line, separated by a single space. The first number is the earliest possible time (in seconds) when all ants fall off the pole (if the directions of their walks are chosen appropriately), and the second number is the latest possible such time.

Sample Input

  1. 2
  2. 10 3
  3. 2 6 7
  4. 214 7
  5. 11 12 7 13 176 23 191
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Output for Sample Input

  1. 4 8
  2. 38 207
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University of Debrecen; Faculty of Informatics; v. 03/01/2019