Submission #527890

#	Time	Username	Problem	Language	Result	Execution time	Memory
527890		rainboy	코알라 (JOI13_koala)	C11	100 / 100	50 ms	6088 KiB

koala

#include <stdio.h>

#define N	100002
#define INF	0x3f3f3f3f3f3f3f3fLL

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

unsigned int X = 12345;

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

int rr[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)
			if (rr[ii[j]] == rr[i_])
				j++;
			else if (rr[ii[j]] < rr[i_]) {
				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;
	}
}

void update(long long *ft, int i, int n, long long x) {
	while (i < n) {
		ft[i] = max(ft[i], x);
		i |= i + 1;
	}
}

long long query(long long *ft, int i) {
	long long x = -INF;

	while (i >= 0) {
		x = max(x, ft[i]);
		i &= i + 1, i--;
	}
	return x;
}

int main() {
	static int xx[N], bb[N], ii[N];
	static long long dp[N], ft1[N], ft2[N];
	int n, xl, xr, d, a, i, r;

	scanf("%d%d%d%d%d", &xl, &xr, &d, &a, &n);
	xx[0] = xl;
	for (i = 1; i <= n; i++)
		scanf("%d%d", &xx[i], &bb[i]);
	xx[n + 1] = xr;
	n += 2;
	for (i = 0; i < n; i++) {
		rr[i] = xx[i] % d;
		ii[i] = i;
	}
	sort(ii, 0, n);
	for (i = 0, r = 0; i < n; i++)
		rr[ii[i]] = i + 1 == n || rr[ii[i + 1]] != rr[ii[i]] ? r++ : r;
	for (i = 0; i < n; i++)
		ft1[i] = ft2[i] = -INF;
	for (i = 0; i < n; i++) {
		dp[i] = i == 0 ? 0 : max(query(ft1, rr[i] - 1) - a, query(ft2, n - 1 - rr[i])) + bb[i];
		update(ft1, rr[i], n, dp[i]);
		update(ft2, n - 1 - rr[i], n, dp[i]);
	}
	printf("%lld\n", dp[n - 1] - (long long) (xx[n - 1] / d - xx[0] / d) * a);
	return 0;
}

Compilation message (stderr)

koala.c: In function 'main':
koala.c:57:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |  scanf("%d%d%d%d%d", &xl, &xr, &d, &a, &n);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
koala.c:60:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |   scanf("%d%d", &xx[i], &bb[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 50 / 50