HDU 3033 I love sneakers! / 分组背包

有k类物品 至少每种选一个 求最大价值

考虑只有一类物品 那么就是01背包了 现在k类 那就多加一维好了

dp[i][k] = max(max(dp[i][k], dp[i][k-x]+y), dp[i-1][k-x]+y);

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
using namespace std;
const int maxn = 110;
vector <int> G[maxn];
int a[maxn], b[maxn], c[maxn];
int dp[maxn][maxn*maxn];

int main()
{
	
	int n, m, t;
	while(scanf("%d %d %d", &n, &m, &t) != EOF)
	{
		for(int i = 1; i <= t; i++)
			G[i].clear();
		for(int i = 1; i <= n; i++)
		{
			scanf("%d %d %d", &a[i], &b[i], &c[i]);
			G[a[i]].push_back(i);
		}
		for(int i = 1; i <= t; i++)
			for(int j = 0; j <= m; j++)
				dp[i][j] = -999999999;
		for(int i = 0; i <= m; i++)
			dp[0][i] = 0;	
		for(int i = 1; i <= t; i++)
		{
			if(G[i].size() == 0)
				break;
			for(int j = 0; j < G[i].size(); j++)
			{
				int x = b[G[i][j]];
				int y = c[G[i][j]];
				for(int k = m; k >= x; k--)
				{
					dp[i][k] = max(max(dp[i][k], dp[i][k-x]+y), dp[i-1][k-x]+y);
				}
			}
		}
		if(dp[t][m] < 0)
			puts("Impossible");
		else
			printf("%d\n", dp[t][m]);
	
	}
	return 0;
}
/*
3 5 3
1 2 5
2 2 1
3 2 2
*/