No Need
题目描述
AtCoDeer the deer has N cards with positive integers written on them. The number on the i-th card (1≤i≤N) is ai. Because he loves big numbers, he calls a subset of the cards good when the sum of the numbers written on the cards in the subset, is K or greater.
Then, for each card i, he judges whether it is unnecessary or not, as follows:
If, for any good subset of the cards containing card i, the set that can be obtained by eliminating card i from the subset is also good, card i is unnecessary.
Otherwise, card i is NOT unnecessary.
Find the number of the unnecessary cards. Here, he judges each card independently, and he does not throw away cards that turn out to be unnecessary.
Constraints
All input values are integers.
1≤N≤5000
1≤K≤5000
1≤ai≤109(1≤i≤N)
Partial Score
300 points will be awarded for passing the test set satisfying N,K≤400.
输入
The input is given from Standard Input in the following format:
N K
a1 a2 … aN
输出
Print the number of the unnecessary cards.
样例输入 Copy
3 6
1 4 3
样例输出 Copy
1
提示
There are two good sets: {2,3} and {1,2,3}.
Card 1 is only contained in {1,2,3}, and this set without card 1, {2,3}, is also good. Thus, card 1 is unnecessary.
For card 2, a good set {2,3} without card 2, {3}, is not good. Thus, card 2 is NOT unnecessary.
Neither is card 3 for a similar reason, hence the answer is 1.
待补
先把博客扔这：
背包dp
二分+bitset
bitset介绍及常用用法