Submission #784034

#	Time	Username	Problem	Language	Result	Execution time	Memory
784034		rainboy	Knapsack (NOI18_knapsack)	C11	100 / 100	63 ms	3468 KiB

knapsack

#include <stdio.h>
#include <string.h>

#define N	100000
#define M	2000

int max(int a, int b) { return a > b ? a : b; }

unsigned int X = 12345;

int rand_() {
	return (X *= 3) >> 1;
}

int vv[N], ww[N], kk[N];

void sort(int *ii, int l, int r) {
	while (l < r) {
		int i = l, j = l, k = r, i_ = ii[l + rand_() % (r - l)], tmp;
		
		while (j < k) {
			int c = ww[ii[j]] != ww[i_] ? ww[ii[j]] - ww[i_] : vv[i_] - vv[ii[j]];

			if (c == 0)
				j++;
			else if (c < 0) {
				tmp = ii[i], ii[i] = ii[j], ii[j] = tmp;
				i++, j++;
			} else {
				k--;
				tmp = ii[j], ii[j] = ii[k], ii[k] = tmp;
			}
		}
		sort(ii, l, i);
		l = k;
	}
}

int main() {
	static int ii[N], dp[M + 1];
	int n, m, h, i, s, k, ans;

	scanf("%d%d", &m, &n);
	for (i = 0; i < n; i++) {
		scanf("%d%d%d", &vv[i], &ww[i], &kk[i]);
		ii[i] = i;
	}
	sort(ii, 0, n);
	memset(dp, -1, (m + 1) * sizeof *dp), dp[0] = 0;
	for (h = 0, k = 0; h < n; h++) {
		i = ii[h];
		if (h == 0 || ww[i] != ww[ii[h - 1]])
			k = m / ww[i];
		while (kk[i] > 0 && k > 0) {
			for (s = m; s >= ww[i]; s--)
				if (dp[s - ww[i]] != -1)
					dp[s] = max(dp[s], dp[s - ww[i]] + vv[i]);
			kk[i]--, k--;
		}
	}
	ans = 0;
	for (s = 0; s <= m; s++)
		ans = max(ans, dp[s]);
	printf("%d\n", ans);
	return 0;
}

Compilation message (stderr)

knapsack.c: In function 'main':
knapsack.c:43:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |  scanf("%d%d", &m, &n);
      |  ^~~~~~~~~~~~~~~~~~~~~
knapsack.c:45:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 |   scanf("%d%d%d", &vv[i], &ww[i], &kk[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 17 / 17
• Subtask 3: 20 / 20
• Subtask 4: 24 / 24
• Subtask 5: 27 / 27