題目

https://www.luogu.org/problemnew/show/P1107

解題思路

設 $f\left[i\right]\left[j\right]$

程式碼

#include<cstdio>
#include<string>
#define rr register
using namespace std; 
int f[2101][2101],n,m,h,g[2101],a[2101][2101]; 
inline int maxx(int x,int y){if (x>y) return x; return y;}
inline int read()
{
	int p=0;  char c=getchar(); 
	while (!isdigit(c)) c=getchar(); 
	while (isdigit(c)) p=(p<<3)+(p<<1)+c-48,c=getchar(); 
	return p; 
}
int main()
{
	n=read(),h=read(),m=read();
	for (rr int i=1;i<=n;++i)
	 {
	 	int w=read(),t; 
	 	for (rr int j=1;j<=w;++j) a[i][t=read()]++; 
	 }
	for (rr int i=h;i;--i)
	{
		for (rr int j=1;j<=n;++j) f[i][j]=f[i+1][j]+a[j][i]; 
		if (i<=h-m) 
			for (rr int j=1;j<=n;++j)  
			f[i][j]=maxx(f[i][j],g[i+m]+a[j][i]); 	
		for (rr int j=1;j<=n;++j) g[i]=maxx(f[i][j],g[i]); 
	}
	printf("%d",g[1]); 
}