OJ Board

Thanks to Jan, I got AC.

These are all the 18 solutions for N = 7:
1 1 3
1 1 4
1 6 3
1 6 4
2 2 1
2 2 6
2 5 1
2 5 6
3 3 2
3 3 5
3 4 2
3 4 5
4 4 2
4 4 5
5 5 1
5 5 6
6 6 3
6 6 4
Good luck

Is there anyone who can explain the sample to me? Thanks.

It's O(N^2) DP

"For any unshaded space b, there is a sequence of unshaded spaces starting at b and ending at a space on the edge of the grid where consecutive spaces in this sequence share a side or a corner. "

Is there anyone who can provide some tests for me? I got so many WAs. Here is my code: #include <iostream> using namespace std; #define MaxN 20005 #define MaxSize 200 #define MaxHash 300000 typedef int List[6]; int Test, N, Total = 0; char Map[4][MaxN]; List E, State[MaxSize]; int Serial[MaxHash], T...

Enumerate each pair of the boats, and check in which time they will get collision, it's a quadratic about the time.

A Hint:
(a + b + c)^2 = a^2 + b^2 + c^2 + 2(xy + yz + zx)

At least my solution uses it. And yes, then the biggest trouble is the precision.

Can anyone provide some tricky test? It's such a troublesome code.

Thank you so much.

My solution is DP, and runs O(N^2) can U tell me more details? I do not know how to dp. THX When we have arranged the first i trees on the left side and j trees on the right side, we use F [j] to denote the minimum distance these trees need to be moved. It should be easy for you to write the equati...

Your answers are correct for this test.

My greedy solution is like this: when you need to remove an object, you should chose the one which will appear again at the latest.

My solution is DP, and runs O(N^2)

The graph should be a simple indirected one.

Pay attention to the word 'simple'.

Can anyone explain the algorithm to this problem?