hdu 2126 Buy the souvenirs 二维01背包方案总数

Buy the souvenirs

Time Limit: 10000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)

Problem Description

When
the winter holiday comes, a lot of people will have a trip. Generally,
there are a lot of souvenirs to sell, and sometimes the travelers will
buy some ones with pleasure. Not only can they give the souvenirs to
their friends and families as gifts, but also can the souvenirs leave
them good recollections. All in all, the prices of souvenirs are not
very dear, and the souvenirs are also very lovable and interesting. But
the money the people have is under the control. They can’t buy a lot,
but only a few. So after they admire all the souvenirs, they decide to
buy some ones, and they have many combinations to select, but there are
no two ones with the same kind in any combination. Now there is a blank
written by the names and prices of the souvenirs, as a top coder all
around the world, you should calculate how many selections you have, and
any selection owns the most kinds of different souvenirs. For instance:

And
you have only 7 RMB, this time you can select any combination with 3
kinds of souvenirs at most, so the selections of 3 kinds of souvenirs
are ABC (6), ABD (7). But if you have 8 RMB, the selections with the
most kinds of souvenirs are ABC (6), ABD (7), ACD (8), and if you have
10 RMB, there is only one selection with the most kinds of souvenirs to
you: ABCD (10).

 

Input

For the first line, there is a T means the number cases, then T cases follow.
In
each case, in the first line there are two integer n and m, n is the
number of the souvenirs and m is the money you have. The second line
contains n integers; each integer describes a kind of souvenir.
All
the numbers and results are in the range of 32-signed integer, and
0<=m<=500, 0<n<=30, t<=500, and the prices are all
positive integers. There is a blank line between two cases.

 

Output

If
you can buy some souvenirs, you should print the result with the same
formation as “You have S selection(s) to buy with K kind(s) of
souvenirs”, where the K means the most kinds of souvenirs you can buy,
and S means the numbers of the combinations you can buy with the K kinds
of souvenirs combination. But sometimes you can buy nothing, so you
must print the result “Sorry, you can't buy anything.”

 

Sample Input

2
4 7
1 2 3 4

4 0
1 2 3 4

 

Sample Output

You have 2 selection(s) to buy with 3 kind(s) of souvenirs.
Sorry, you can't buy anything.

 

Author

wangye

 

Source

HDU 2007-10 Programming Contest

思路：在01背包的方案dp方程再加一维，记录K；

　　　　dp[i][t]+=dp[i-a[j]][t-1];

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define esp 0.00000000001
const int N=1e3+,M=1e6+,inf=1e9+,mod=;
int a[N];
int dp[N][N];
int main()
{
    int x,y,z,i,t;
    int T;
    scanf("%d",&T);
    while(T--)
    {
        memset(dp,,sizeof(dp));
        scanf("%d%d",&x,&y);
        for(i=;i<=x;i++)
        scanf("%d",&a[i]);
        dp[][]=;
        for(i=;i<=x;i++)
        {
            for(t=y;t>=a[i];t--)
            {
                for(int j=;j<x;j++)
                dp[t][j+]+=dp[t-a[i]][j];
            }
        }
        int ans=;
        for(t=x;t>=;t--)
        {
            ans=;
            for(i=;i<=y;i++)
            ans+=dp[i][t];
            if(ans>)break;
        }
        if(t>)
        printf("You have %d selection(s) to buy with %d kind(s) of souvenirs.\n",ans,t);
        else
        printf("Sorry, you can't buy anything.\n");
    }
    return ;
}