Submission #544777

#	Time	Username	Problem	Language	Result	Execution time	Memory
544777		rainboy	MP3 Player (CEOI10_mp3player)	C11	100 / 100	63 ms	5120 KiB

mp3player

#include <stdio.h>

#define N	100000
#define N_	(1 << 17)

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

unsigned int X = 12345;

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

int tt[N]; char cc[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 (tt[ii[j]] == tt[i_])
				j++;
			else if (tt[ii[j]] < tt[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 sum[N_ * 2], sufmn[N_ * 2], sufmx[N_ * 2], n_;

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

	sum[i] = sum[l] + sum[r];
	sufmn[i] = min(sufmn[l] + sum[r], sufmn[r]);
	sufmx[i] = max(sufmx[l] + sum[r], sufmx[r]);
}

void build(char *cc, int n) {
	int i;

	n_ = 1;
	while (n_ < n)
		n_ <<= 1;
	for (i = 1; i < n; i++)
		sum[n_ + i] = cc[i] == '+' ? 1 : -1, sufmn[n_ + i] = min(sum[n_ + i], 0), sufmx[n_ + i] = max(sum[n_ + i], 0);
	for (i = n_ - 1; i > 0; i--)
		pul(i);
}

void update(int i) {
	i += n_;
	sum[i] = sufmn[i] = sufmx[i] = 0;
	while (i > 1)
		pul(i >>= 1);
}

int mn, mx;

void query(int d) {
	int i, s;

	i = 1, s = mn = mx = 0;
	while (i < n_) {
		int s_ = s + sum[i << 1 | 1];
		int mn_ = min(mn, sufmn[i << 1 | 1] + s);
		int mx_ = max(mx, sufmx[i << 1 | 1] + s);

		if (mx_ - mn_ <= d)
			s = s_, mn = mn_, mx = mx_, i = i << 1 | 0;
		else
			i = i << 1 | 1;
	}
}

int main() {
	static int ii[N];
	int n, vmax, v2, i;

	scanf("%d%d%d", &n, &vmax, &v2);
	for (i = 0; i < n; i++) {
		static char s[2];

		scanf("%s%d", s, &tt[i]);
		cc[i] = s[0];
	}
	for (i = n - 1; i > 0; i--) {
		tt[i] -= tt[i - 1];
		ii[i] = i;
	}
	sort(ii, 1, n);
	build(cc, n);
	i = n - 1;
	while (1) {
		int t;

		query(vmax);
		if (mx <= v2 && v2 <= vmax + mn) {
			if (i + 1 == n)
				printf("infinity\n");
			else
				printf("%d %d\n", tt[ii[i + 1]] - 1, v2 == vmax + mn ? vmax : v2 - sum[1]);
			return 0;
		}
		t = tt[ii[i]];
		while (i >= 0 && tt[ii[i]] == t)
			update(ii[i--]);
	}
	return 0;
}

Compilation message (stderr)

mp3player.c: In function 'main':
mp3player.c:87:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   87 |  scanf("%d%d%d", &n, &vmax, &v2);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mp3player.c:91:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |   scanf("%s%d", s, &tt[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10