HDU 2639 Bone Collector II (0-1背包第k优解)

http://acm.hdu.edu.cn/showproblem.php?pid=2639


参考背包九讲9.5节,注意合并单调队列的技巧(末尾加一个-1标记)


完整代码:

/*109ms,488KB*/

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<functional>
using namespace std;

int w[105], v[105], dp[1005][65], tmp1[35], tmp2[35];

///a+b->c,集合去重型合并,按从大到小的顺序
void set_unique_union(int a[], int b[], int c[], int k)
{
	int x = 1, y = 1, z = 1;///便于判重
	while (z <= k && (a[x] >= 0 || b[y] >= 0))
	{
		c[z] = (a[x] > b[y] ? a[x++] : b[y++]);
		if (c[z] != c[z - 1]) ++z;
	}
}

int _01pack(int n, int maxw, int k)
{
	memset(dp, 0, sizeof(dp));
	memset(tmp1, 0, sizeof(tmp1));
	memset(tmp2, 0, sizeof(tmp2));
	int i, j, p, x, y, z;
	for (i = 0; i < n; ++i)
	{
		for (j = maxw; j >= w[i]; --j)
		{
			memcpy(tmp1 + 1, dp[j] + 1, sizeof(int) * k);
			for (p = 1; p <= k; ++p) tmp2[p] = dp[j - w[i]][p] + v[i];
			tmp1[k + 1] = tmp2[k + 1] = -1;
			set_unique_union(tmp1, tmp2, dp[j], k);
		}
	}
	return dp[maxw][k];
}

int main()
{
	int t, n, maxw, i, k;
	scanf("%d", &t);
	while (t--)
	{
		scanf("%d%d%d", &n, &maxw, &k);
		for (i = 0; i < n; ++i) scanf("%d", &v[i]);
		for (i = 0; i < n; ++i) scanf("%d", &w[i]);
		printf("%d\n", _01pack(n, maxw, k));
	}
	return 0;
}

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