hdu2546 饭卡 (01背包)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAXN 1002

int cmp(const void *x,const void *y)
{
	return *(int *)x-*(int *)y;
}

int Max(int x,int y)
{
	if(x>y)
		return x;
	else
		return y;
}

int main()
{
	int n,i,j,m;
	int price[MAXN],dp[MAXN];
	while(scanf("%d",&n)&&n)
	{
		memset(dp,0,sizeof(dp));
		for(i=0;i<n;++i)
			scanf("%d",&price[i]);
		qsort(price,n,sizeof(price[0]),cmp);
		scanf("%d",&m);
		if(m<5)
		{
			printf("%d\n",m);
			continue;
		}
		m-=5;//用5元购买最贵的菜
		for (i=0;i<n-1;++i)
		{
			for(j=m;j>=price[i];--j)
				dp[j]=Max(dp[j],dp[j-price[i]]+price[i]);
		}
		printf("%d\n",m+5-dp[m]-price[n-1]);
	}
	return 0;
}