【USACO题库】3.4.4 Raucous Rockers“破锣摇滚”乐队

此题DP即可

设f[i][j]表示已经装了i张CD，当前CD还剩下j分钟的最大歌曲数目

#include<cstdio>
#include<algorithm>
using namespace std;
int a[21],f[21][21],n,t,m;

inline int read()
{
	int x=0; char c=getchar();
	while (c<'0' || c>'9') c=getchar();
	while (c>='0' && c<='9') x=(x<<1)+(x<<3)+(c^48),c=getchar();
	return x;
}

int main()
{
	freopen("rockers.in","r",stdin);
	freopen("rockers.out","w",stdout);
	n=read(),t=read(),m=read();
	for (int i=1;i<=n;i++) a[i]=read();
	for (int k=1;k<=n;k++)
		for (int i=m;i>0;i--)
			for (int j=t;j>=a[k];j--)
				f[i][j]=max(f[i][j],max(f[i-1][t],f[i][j-a[k]])+1);
	printf("%d\n",f[m][t]);
	return 0;
}