HDU - 2844 Coins

題意：問可以得到多少種可能湊成的價格

思路：完全背包的模板

#include 
#include 
#include 
#include 
using namespace std;
const int MAXN = 110;

int val[MAXN],num[MAXN];
int f[100005],n,v;

int main(){
	while (scanf("%d%d",&n,&v) != EOF && n+v){
		for (int i = 1; i <= n; i++)
			scanf("%d",&val[i]);
		for (int i = 1; i <= n; i++)
			scanf("%d",&num[i]);
		memset(f,0,sizeof(f));
		f[0] = 1;
		for (int i = 1; i <= n; i++){
			int x = val[i],y = num[i];
			int t = 1;
			while (y){
				for (int j = v; j >= x*t; j--)
					if (f[j-x*t])
						f[j] = 1;
				y -= t;
				t = min(y,2*t);
			}
		}
		int ans = 0;
		for (int i = 1; i <= v; i++)
			ans += f[i];
		printf("%d\n",ans);
	}
}