题址:http://acm.hdu.edu.cn/showproblem.php?pid=1864
0—1背包,把每张发票当一个物品, 其中,发票中有单项大于600的或者总额大于1000的,这张发票扔掉不要,也就是不加入物品的行列。整理出每张发票的总额,作为这件物品的价值也作为容量(相当于物品的体积),放到容量为q的背包中,这就是标准的0—1背包了;
转移方程:f[j]=max(f[j],f[j-1]+v[i]);
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
using namespace std;
const int Inf = 3000010;
const int INF = 35;
int ans[Inf], arr[INF];
int q, n, m;
void Zero_onepack(int k)
{
memset(ans, 0, sizeof(ans));
for(int i = 0; i < k; ++ i)
{
for(int j = q; j >= arr[i]; -- j)
{
if(ans[j-arr[i]] + arr[i] > ans[j])
ans[j] = ans[j-arr[i]] + arr[i];
}
}
double rez = (double)ans[q]/100.0;
printf("%.2lf\n", rez);
}
void init()
{
double a;
char ch, ch1;
while(cin >> a >> n && n)
{
q = (int)(a*100.0);
int k = 0;
memset(arr, 0, sizeof(arr));
for(int i = 0; i < n; ++ i)
{
cin >> m;
bool flag = false;
int A = 0, B = 0, C = 0;
for(int j = 0; j < m; ++ j)
{
cin >> ch >> ch1 >> a;
//cout << ch << " " << ch1 << " " << a;
if(ch == 'A')
A += (int)(a*100);
else if(ch == 'B')
B += (int)(a*100);
else if(ch == 'C')
C += (int)(a*100);
else
{
flag = true;
break;
}
}
if(flag || A > 60000 || B > 60000 || C > 60000 || (A+B+C) > 100000) continue;
arr[k ++] = A + B + C;
}
Zero_onepack(k);
}
}
int main()
{
init();
return 0;
}