poj 3628 Bookshelf 2

http://poj.org/problem?id=3628

01背包

 1 #include <cstdio>

 2 #include <iostream>

 3 #include <cstring>

 4 #include <algorithm>

 5 #define maxn 21

 6 #define ll long long

 7 using namespace std;

 8 

 9 ll h[maxn];

10 int n;

11 ll b;

12 ll dp[1000004];

13 ll max1(ll a,ll b)

14 {

15     return a>b?a:b;

16 }

17 

18 int main()

19 {

20     while(scanf("%d%lld",&n,&b)!=EOF)

21     {

22         ll v=0;

23         for(int i=1; i<=n; i++)

24         {

25             scanf("%lld",&h[i]);

26             v+=h[i];

27         }

28         for(int i=1; i<=n; i++)

29         {

30             for(ll j=v; j>=h[i]; j--)

31             {

32                 dp[j]=max(dp[j-h[i]]+h[i],dp[j]);

33             }

34         }

35         for(ll j=1; j<=v; j++)

36         {

37             if(dp[j]>=b)

38             {

39               printf("%lld\n",dp[j]-b);

40               break;

41             }

42         }

43     }

44     return 0;

45 }

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