oj.uz

Submission #545942

# Submission time Handle Problem Language Result Execution time Memory
545942 2022-04-05T16:15:48 Z rainboy Star Trek (CEOI20_startrek) C
100 / 100
 87 ms 18388 KB 
#include <stdio.h>
#include <stdlib.h>

#define N	100000
#define MD	1000000007

int *ej[N], eo[N];

void append(int i, int j) {
	int o = eo[i]++;

	if (o >= 2 && (o & o - 1) == 0)
		ej[i] = (int *) realloc(ej[i], o * 2 * sizeof *ej[i]);
	ej[i][o] = j;
}

char dp[N], dq[N]; int dr[N][2], ds[N][2];

void dfs1(int p, int i) {
	int o, j_, sum0, sum1;

	dp[i] = 0, j_ = -1, sum0 = 0, sum1 = 0;
	for (o = eo[i]; o--; ) {
		int j = ej[i][o];

		if (j != p) {
			dfs1(i, j);
			sum0 += dr[j][0], sum1 += dr[j][1];
			if (!dp[j]) {
				dp[i] = 1;
				if (j_ == -1)
					j_ = j;
				else
					j_ = -2;
			}
		}
	}
	if (j_ == -1)
		dr[i][0] = sum1, dr[i][1] = sum0 + 1;
	else if (j_ != -2)
		dr[i][0] = dr[j_][1], dr[i][1] = sum0 + sum1 - dr[j_][1] + 1;
	else
		dr[i][0] = 0, dr[i][1] = sum0 + sum1 + 1;
}

void dfs2(int p, int i) {
	int o, j1, j2, sum0, sum1;

	j1 = -1, j2 = -1, sum0 = ds[i][0], sum1 = ds[i][1];
	for (o = eo[i]; o--; ) {
		int j = ej[i][o];

		if (j != p) {
			sum0 += dr[j][0], sum1 += dr[j][1];
			if (!dp[j]) {
				if (j1 == -1)
					j1 = j;
				else if (j2 == -1)
					j2 = j;
				else
					j1 = j2 = -2;
			}
		}
	}
	if (dq[i])
		for (o = eo[i]; o--; ) {
			int j = ej[i][o];

			if (j != p) {
				int sum0_ = sum0 - dr[j][0], sum1_ = sum1 - dr[j][1];

				if (j1 == -1 || j2 == -1 && j == j1)
					dq[j] = 0, ds[j][0] = sum1_, ds[j][1] = sum0_ + 1;
				else if (j2 == -1 || j == j2)
					dq[j] = 1, ds[j][0] = dr[j1][1], ds[j][1] = sum0_ + sum1_ - dr[j1][1] + 1;
				else if (j == j1)
					dq[j] = 1, ds[j][0] = dr[j2][1], ds[j][1] = sum0_ + sum1_ - dr[j2][1] + 1;
				else
					dq[j] = 1, ds[j][0] = 0, ds[j][1] = sum0_ + sum1_ + 1;
			}
		}
	else
		for (o = eo[i]; o--; ) {
			int j = ej[i][o];

			if (j != p) {
				int sum0_ = sum0 - dr[j][0], sum1_ = sum1 - dr[j][1];

				dq[j] = 1;
				if (j1 == -1 || j2 == -1 && j == j1)
					ds[j][0] = ds[i][1], ds[j][1] = sum0_ + sum1_ - ds[i][1] + 1;
				else
					ds[j][0] = 0, ds[j][1] = sum0_ + sum1_ + 1;
			}
		}
	if (dq[i]) {
		if (j1 == -1)
			dr[i][0] = sum1, dr[i][1] = sum0 + 1;
		else if (j2 == -1)
			dr[i][0] = dr[j1][1], dr[i][1] = sum0 + sum1 - dr[j1][1] + 1;
		else
			dr[i][0] = 0, dr[i][1] = sum0 + sum1 + 1;
	} else {
		dp[i] = 1;
		if (j1 == -1)
			dr[i][0] = ds[i][1], dr[i][1] = sum0 + sum1 - ds[i][1] + 1;
		else
			dr[i][0] = 0, dr[i][1] = sum0 + sum1 + 1;
	}
	for (o = eo[i]; o--; ) {
		int j = ej[i][o];

		if (j != p)
			dfs2(i, j);
	}
}

void mult(int aa[][2], int bb[][2], int cc[][2]) {
	cc[0][0] = ((long long) aa[0][0] * bb[0][0] + (long long) aa[0][1] * bb[1][0]) % MD;
	cc[0][1] = ((long long) aa[0][0] * bb[0][1] + (long long) aa[0][1] * bb[1][1]) % MD;
	cc[1][0] = ((long long) aa[1][0] * bb[0][0] + (long long) aa[1][1] * bb[1][0]) % MD;
	cc[1][1] = ((long long) aa[1][0] * bb[0][1] + (long long) aa[1][1] * bb[1][1]) % MD;
}

void power(int aa[][2], int pp[][2], int tt[][2], long long k) {
	if (k == 0) {
		pp[0][0] = 1, pp[0][1] = 0;
		pp[1][0] = 0, pp[1][1] = 1;
		return;
	}
	if (k % 2 == 0) {
		power(aa, tt, pp, k / 2);
		mult(tt, tt, pp);
	} else {
		power(aa, pp, tt, k / 2);
		mult(pp, pp, tt);
		mult(tt, aa, pp);
	}
}

int main() {
	static int aa[2][2], pp[2][2], tt[2][2];
	int n, h, i, j, x, y, k0, k1, ans;
	long long d;

	scanf("%d%lld", &n, &d);
	for (i = 0; i < n; i++)
		ej[i] = (int *) malloc(2 * sizeof *ej[i]);
	for (h = 0; h < n - 1; h++) {
		scanf("%d%d", &i, &j), i--, j--;
		append(i, j), append(j, i);
	}
	dfs1(-1, 0);
	dq[0] = 1;
	dfs2(-1, 0);
	k0 = k1 = 0;
	for (i = 0; i < n; i++) {
		aa[0][0] = (aa[0][0] + dr[i][0]) % MD;
		aa[1][0] = (aa[1][0] + dr[i][1]) % MD;
		if (!dp[i])
			k0++, aa[0][1] = (aa[0][1] + n) % MD;
		else
			k1++, aa[1][1] = (aa[1][1] + n) % MD;
	}
	power(aa, pp, tt, d - 1);
	x = ((long long) pp[0][0] * k0 + (long long) pp[0][1] * k1) % MD;
	y = ((long long) pp[1][0] * k0 + (long long) pp[1][1] * k1) % MD;
	ans = 0;
	if (dp[0])
		ans = (ans + (long long) n * y) % MD;
	ans = (ans + (long long) dr[0][1] * x) % MD;
	printf("%d\n", ans);
	return 0;
}

Compilation message

startrek.c: In function 'append':
startrek.c:12:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   12 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
startrek.c: In function 'dfs2':
startrek.c:72:30: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   72 |     if (j1 == -1 || j2 == -1 && j == j1)
      |                     ~~~~~~~~~^~~~~~~~~~
startrek.c:90:30: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   90 |     if (j1 == -1 || j2 == -1 && j == j1)
      |                     ~~~~~~~~~^~~~~~~~~~
startrek.c: In function 'main':
startrek.c:146:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  146 |  scanf("%d%lld", &n, &d);
      |  ^~~~~~~~~~~~~~~~~~~~~~~
startrek.c:150:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  150 |   scanf("%d%d", &i, &j), i--, j--;
      |   ^~~~~~~~~~~~~~~~~~~~~

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 288 KB Output is correct
2 Correct 1 ms 296 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 296 KB Output is correct
2 Correct 0 ms 288 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct

Subtask #3
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 344 KB Output is correct
6 Correct 1 ms 212 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 344 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct

Subtask #5
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 344 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 72 ms 12520 KB Output is correct
13 Correct 87 ms 18356 KB Output is correct
14 Correct 66 ms 7500 KB Output is correct
15 Correct 80 ms 7628 KB Output is correct
16 Correct 70 ms 7648 KB Output is correct

Subtask #6
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 344 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 288 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 288 KB Output is correct
15 Correct 1 ms 212 KB Output is correct
16 Correct 0 ms 212 KB Output is correct
17 Correct 0 ms 340 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 0 ms 212 KB Output is correct
20 Correct 0 ms 212 KB Output is correct
21 Correct 1 ms 340 KB Output is correct
22 Correct 1 ms 468 KB Output is correct
23 Correct 1 ms 340 KB Output is correct
24 Correct 1 ms 296 KB Output is correct
25 Correct 1 ms 340 KB Output is correct
26 Correct 1 ms 340 KB Output is correct
27 Correct 1 ms 468 KB Output is correct
28 Correct 1 ms 340 KB Output is correct
29 Correct 1 ms 340 KB Output is correct
30 Correct 1 ms 340 KB Output is correct

Subtask #7
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 344 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 72 ms 12520 KB Output is correct
13 Correct 87 ms 18356 KB Output is correct
14 Correct 66 ms 7500 KB Output is correct
15 Correct 80 ms 7628 KB Output is correct
16 Correct 70 ms 7648 KB Output is correct
17 Correct 1 ms 288 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 1 ms 288 KB Output is correct
20 Correct 1 ms 212 KB Output is correct
21 Correct 0 ms 212 KB Output is correct
22 Correct 0 ms 340 KB Output is correct
23 Correct 0 ms 212 KB Output is correct
24 Correct 0 ms 212 KB Output is correct
25 Correct 0 ms 212 KB Output is correct
26 Correct 1 ms 340 KB Output is correct
27 Correct 1 ms 468 KB Output is correct
28 Correct 1 ms 340 KB Output is correct
29 Correct 1 ms 296 KB Output is correct
30 Correct 1 ms 340 KB Output is correct
31 Correct 1 ms 340 KB Output is correct
32 Correct 1 ms 468 KB Output is correct
33 Correct 1 ms 340 KB Output is correct
34 Correct 1 ms 340 KB Output is correct
35 Correct 1 ms 340 KB Output is correct
36 Correct 70 ms 12512 KB Output is correct
37 Correct 72 ms 18388 KB Output is correct
38 Correct 52 ms 7528 KB Output is correct
39 Correct 73 ms 7528 KB Output is correct
40 Correct 67 ms 7644 KB Output is correct
41 Correct 62 ms 15576 KB Output is correct
42 Correct 64 ms 16844 KB Output is correct
43 Correct 52 ms 6736 KB Output is correct
44 Correct 62 ms 7536 KB Output is correct
45 Correct 59 ms 7640 KB Output is correct

Subtask #8
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 288 KB Output is correct
2 Correct 1 ms 296 KB Output is correct
3 Correct 0 ms 296 KB Output is correct
4 Correct 0 ms 288 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 1 ms 344 KB Output is correct
13 Correct 1 ms 212 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 340 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 72 ms 12520 KB Output is correct
20 Correct 87 ms 18356 KB Output is correct
21 Correct 66 ms 7500 KB Output is correct
22 Correct 80 ms 7628 KB Output is correct
23 Correct 70 ms 7648 KB Output is correct
24 Correct 1 ms 288 KB Output is correct
25 Correct 1 ms 340 KB Output is correct
26 Correct 1 ms 288 KB Output is correct
27 Correct 1 ms 212 KB Output is correct
28 Correct 0 ms 212 KB Output is correct
29 Correct 0 ms 340 KB Output is correct
30 Correct 0 ms 212 KB Output is correct
31 Correct 0 ms 212 KB Output is correct
32 Correct 0 ms 212 KB Output is correct
33 Correct 1 ms 340 KB Output is correct
34 Correct 1 ms 468 KB Output is correct
35 Correct 1 ms 340 KB Output is correct
36 Correct 1 ms 296 KB Output is correct
37 Correct 1 ms 340 KB Output is correct
38 Correct 1 ms 340 KB Output is correct
39 Correct 1 ms 468 KB Output is correct
40 Correct 1 ms 340 KB Output is correct
41 Correct 1 ms 340 KB Output is correct
42 Correct 1 ms 340 KB Output is correct
43 Correct 70 ms 12512 KB Output is correct
44 Correct 72 ms 18388 KB Output is correct
45 Correct 52 ms 7528 KB Output is correct
46 Correct 73 ms 7528 KB Output is correct
47 Correct 67 ms 7644 KB Output is correct
48 Correct 62 ms 15576 KB Output is correct
49 Correct 64 ms 16844 KB Output is correct
50 Correct 52 ms 6736 KB Output is correct
51 Correct 62 ms 7536 KB Output is correct
52 Correct 59 ms 7640 KB Output is correct
53 Correct 78 ms 18384 KB Output is correct
54 Correct 76 ms 16100 KB Output is correct
55 Correct 39 ms 6180 KB Output is correct
56 Correct 81 ms 12560 KB Output is correct
57 Correct 52 ms 7696 KB Output is correct
58 Correct 64 ms 7700 KB Output is correct
59 Correct 75 ms 7640 KB Output is correct
60 Correct 77 ms 7628 KB Output is correct