Submission #1014865

#	Time	Username	Problem	Language	Result	Execution time	Memory
1014865		rainboy	Flooding Wall (BOI24_wall)	C11	100 / 100	547 ms	36160 KiB

Main

#include <stdio.h>

#define N	500000
#define N_	(1 << 19)	/* N_ = pow2(ceil(log2(N))) */
#define MD	1000000007

unsigned int Z = 12345;

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

int pp2[N + 1];

void init() {
	int i;

	pp2[0] = 1;
	for (i = 1; i <= N; i++)
		pp2[i] = pp2[i - 1] * 2 % MD;
}

int yy[N * 2];

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

int sz[N_ * 2], prod[N_ * 2], pref[N_ * 2], suff[N_ * 2], n_;

void pul(int i) {
	int l = i << 1, r = l | 1;

	prod[i] = (long long) prod[l] * prod[r] % MD;
	pref[i] = ((long long) pref[l] * pp2[sz[r]] + (long long) prod[l] * pref[r]) % MD;
	suff[i] = ((long long) suff[l] * prod[r] + (long long) pp2[sz[l]] * suff[r]) % MD;
}

void build(int n) {
	int i;

	n_ = 1;
	while (n_ < n)
		n_ <<= 1;
	for (i = 0; i < n_; i++)
		if (i < n)
			sz[n_ + i] = 1;
		else
			prod[n_ + i] = 1;
	for (i = n_ - 1; i > 0; i--)
		sz[i] = sz[i << 1 | 0] + sz[i << 1 | 1], pul(i);
}

void update(int i) {
	i += n_;
	pref[i] = suff[i] = ++prod[i];
	while (i > 1)
		pul(i >>= 1);
}

int main() {
	static int ii[N * 2];
	int n, h, i, x, sum, ans;

	init();
	scanf("%d", &n);
	for (i = 0; i < n; i++)
		scanf("%d", &yy[i << 1 | 0]);
	for (i = 0; i < n; i++)
		scanf("%d", &yy[i << 1 | 1]);
	for (i = 0; i < n * 2; i++)
		ii[i] = i;
	sort(ii, 0, n * 2);
	build(n);
	ans = 0;
	for (h = 0; h < n * 2; h++) {
		x = ((long long) pp2[n] * n - pref[1] - suff[1] + (long long) prod[1] * n + MD * 2) % MD;
		ans = (ans + (long long) x * (yy[ii[h]] - (h == 0 ? 0 : yy[ii[h - 1]]))) % MD;
		update(ii[h] >> 1);
	}
	sum = 0;
	for (i = 0; i < n * 2; i++)
		sum = (sum + yy[i]) % MD;
	ans = (ans - (long long) sum * pp2[n - 1] % MD + MD) % MD;
	printf("%d\n", ans);
	return 0;
}

Compilation message (stderr)

Main.c: In function 'main':
Main.c:81:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
Main.c:83:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |   scanf("%d", &yy[i << 1 | 0]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.c:85:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   85 |   scanf("%d", &yy[i << 1 | 1]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 17 / 17
• Subtask 3: 19 / 19
• Subtask 4: 14 / 14
• Subtask 5: 12 / 12
• Subtask 6: 30 / 30