Searching for Nessy |
The Loch Ness Monsteris a mysterious and unidentified animal said to inhabit Loch Ness,
a large deep freshwater loch near the city of Inverness in northern Scotland. Nessie is usually categorized as a type of lake monster.
http://en.wikipedia.org/wiki/Loch_Ness_Monster
In July 2003, the BBC reported an extensive investigation of Loch Ness by a BBC team, using 600 separate sonar beams, found no trace of any ¨sea monster¨ (i.e., any large animal, known or unknown) in the loch. The BBC team concluded that Nessie does not exist. Now we want to repeat the experiment.
Given a grid of n rows and m columns representing the loch, 6n, m10000, find the minimum number s of sonar beams you must put in the square such that we can control every position in the grid, with the following conditions:
- one sonar occupies one position in the grid; the sonar beam controls its own cell and the contiguous cells;
- the border cells do not need to be controlled, because Nessy cannot hide there (she is too big).
For example,
where X represents a sonar, and the shaded cells are controlled by their sonar beams; the last figure gives us a solution.
Input
The first line of the input contains an integer, t, indicating the number of test cases. For each test case, there is a line with two numbers separated by blanks, 6n, m10000, that is, the size of the grid (n rows and m columns).
Output
For each test case, the output should consist of one line showing the minimum number of sonars that verifies the conditions above.
Sample Input
3 6 6 7 7 9 13
Sample Output
4 4 12
貌似题目很长很难,其实很简单,稍微思考一下就可以了,没必要过多解释。这种题目要重视,千万不要被题目的长度吓住了。这种题目是纸老虎。
1 #include <iostream> 2 #include <cstdlib> 3 #include <cstdio> 4 5 using namespace std; 6 7 int main(void) 8 { 9 int n, m, t; 10 11 cin >> t; 12 while (t--) 13 { 14 cin >> n >> m; 15 n -= 2; m-= 2; 16 n = n / 3 + (n % 3 != 0); 17 m = m / 3 + (m % 3 != 0); 18 cout << n * m << endl; 19 } 20 21 return 0; 22 }