Submission #684851

#	Time	Username	Problem	Language	Result	Execution time	Memory
684851		rainboy	Long Distance Coach (JOI17_coach)	C11	100 / 100	192 ms	17864 KiB

coach

#include <stdio.h>

#define N	200002
#define M	200001
#define INF	0x3f3f3f3f3f3f3f3fLL

long long min(long long a, long long b) { return a < b ? a : b; }

unsigned int X = 12345;

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

long long yy[N], aa[N]; int cc[N], n;
long long qq[M], rr[M]; int m;
long long l, t;

long long *vv;

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 (vv[ii[j]] == vv[i_])
				j++;
			else if (vv[ii[j]] < vv[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;
	}
}

long double cross(long long x1, long long y1, long long x2, long long y2) {
	return (long double) x1 * y2 - (long double) x2 * y1;
}

long long dp[N], dq[N];

long double crossp(int i, int j, int k) {
	return cross(j - i, dp[j] - dp[i], k - i, dp[k] - dp[i]);
}

long double crossq(int i, int j, int k) {
	return cross(j - i, dq[j] - dq[i], k - i, dq[k] - dq[i]);
}

long long evalp(int i, long long x) {
	return dp[i] + x * i;
}

long long evalq(int i, long long x) {
	return dq[i] + x * i;
}

int main() {
	static int hh[M], ii[N], qu1[N], qu2[N];
	int cnt1, cnt2, w, g, h, i, j, lower, upper;
	long long x, a, ans;

	scanf("%lld%d%d%d%lld", &l, &m, &n, &w, &t), n += 2, m++;
	for (h = 0; h + 1 < m; h++) {
		scanf("%lld", &x);
		qq[h] = x / t, rr[h] = x % t;
	}
	qq[m - 1] = l / t, rr[h] = l % t;
	for (h = 0; h < m; h++)
		hh[h] = h;
	vv = rr, sort(hh, 0, m);
	yy[0] = 0, cc[0] = 0;
	for (i = 1; i < n; i++)
		scanf("%lld%d", &yy[i], &cc[i]);
	yy[n - 1] = t, cc[n - 1] = 0;
	for (i = 0; i < n; i++)
		ii[i] = i;
	vv = yy, sort(ii, 0, n);
	for (i = 0; i + 1 < n; i++)
		aa[i] = qq[m - 1] + (rr[m - 1] >= yy[ii[i]] ? 1 : 0);
	cnt1 = cnt2 = 0;
	for (j = 0, h = 0; j < n; j++) {
		if (j == 0)
			dp[0] = aa[0] * w - cc[0], dq[0] = INF;
		else {
			a = INF;
			while (h < m && rr[hh[h]] < yy[ii[j]])
				a = min(a, qq[hh[h++]]);
			if (a == INF)
				dq[j] = min(dq[j - 1] + aa[j - 1] * w, dp[j - 1]);
			else {
				dq[j] = INF;
				if (cnt1) {
					lower = -1, upper = cnt1 - 1;
					while (upper - lower > 1) {
						g = (lower + upper) / 2;
						if (evalp(qu1[g], -a * w) > evalp(qu1[g + 1], -a * w))
							lower = g;
						else
							upper = g;
					}
					g = upper;
					dq[j] = min(dq[j], evalp(qu1[g], -a * w) + a * w * (j - 1));
				}
				if (cnt2) {
					lower = -1, upper = cnt2 - 1;
					while (upper - lower > 1) {
						g = (lower + upper) / 2;
						if (evalq(qu2[g], -a * w) > evalq(qu2[g + 1], -a * w))
							lower = g;
						else
							upper = g;
					}
					g = upper;
					dq[j] = min(dq[j], evalq(qu2[g], -a * w) + a * w * j);
				}
			}
			dp[j] = dq[j] + aa[j] * w - cc[ii[j]];
		}
		if (dp[j] != INF) {
			while (cnt1 >= 2 && crossp(qu1[cnt1 - 2], qu1[cnt1 - 1], j) <= 0)
				cnt1--;
			qu1[cnt1++] = j;
		}
		if (dq[j] != INF) {
			while (cnt2 >= 2 && crossq(qu2[cnt2 - 2], qu2[cnt2 - 1], j) <= 0)
				cnt2--;
			qu2[cnt2++] = j;
		}
	}
	ans = dp[n - 1];
	for (i = 0; i < n; i++)
		ans += cc[i];
	printf("%lld\n", ans);
	return 0;
}

Compilation message (stderr)

coach.c: In function 'main':
coach.c:67:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |  scanf("%lld%d%d%d%lld", &l, &m, &n, &w, &t), n += 2, m++;
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
coach.c:69:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |   scanf("%lld", &x);
      |   ^~~~~~~~~~~~~~~~~
coach.c:78:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |   scanf("%lld%d", &yy[i], &cc[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 16 / 16
• Subtask 2: 30 / 30
• Subtask 3: 25 / 25
• Subtask 4: 29 / 29