Description
Each vase has a distinct characteristic (just like flowers do).
Hence, putting a bunch of flowers in a vase results in a certain
aesthetic value, expressed by an integer. The aesthetic values are
presented in a table as shown below. Leaving a vase empty has an
aesthetic value of 0.
V A S E S |
||||||
1 |
2 |
3 |
4 |
5 |
||
Bunches |
1 (azaleas) |
7 | 23 | -5 | -24 | 16 |
2 (begonias) |
5 | 21 | -4 | 10 | 23 | |
3 (carnations) |
-21 |
5 | -4 | -20 | 20 |
According to the table, azaleas, for example, would look great in vase 2, but they would look awful in vase 4.
To achieve the most pleasant effect you have to maximize the sum of
aesthetic values for the arrangement while keeping the required ordering
of the flowers. If more than one arrangement has the maximal sum value,
any one of them will be acceptable. You have to produce exactly one
arrangement.
Input
- The first line contains two numbers: F, V.
- The following F lines: Each of these lines contains V integers, so that Aij is given as the jth number on the (i+1)st line of the input file.
- 1 <= F <= 100 where F is the number of the bunches of flowers. The bunches are numbered 1 through F.
- F <= V <= 100 where V is the number of vases.
- -50 <= Aij <= 50 where Aij is the aesthetic value obtained by putting the flower bunch i into the vase j.
Output
Sample Input
3 5
7 23 -5 -24 16
5 21 -4 10 23
-21 5 -4 -20 20
Sample Output
53
一道很简单的dp,设f[i][j]表示在第j个花瓶装第i朵花并且前i多已经装过的最大美学价值,be[i][j]为把第i朵花放入第j个花瓶的美学价值。
转移方程:f[i][j]=max(f[i-1][k])+be[i][k];(i<=j<=V,k<j)
即前一朵花在k放转移,且题目里要求花的放置必须按次序。
注意,这道题的初值不能赋0,因为be[i][k]>=-50
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
int f[][],be[][];
int main()
{
int ff,v;
while(~scanf("%d%d",&ff,&v))
{
memset(f,-0x3f,sizeof(f));
memset(be,,sizeof(be));
f[][]=;
int ans=-1e4;
for(int i=;i<=ff;i++)
for(int j=;j<=v;j++)
scanf("%d",&be[i][j]);
for(int i=;i<=ff;i++)
for(int j=i;j<=v;j++)
for(int k=;k<j;k++)
f[i][j]=max(f[i][j],f[i-][k]+be[i][j]);
for(int i=;i<=v;i++) ans=max(ans,f[ff][i]);
printf("%d\n",ans);
}
return ;
}