oj.uz

Submission #481343

# Submission time Handle Problem Language Result Execution time Memory
481343 2021-10-20T12:30:06 Z rainboy Lampice (COCI19_lampice) C
73 / 110
 5000 ms 7884 KB 
#include <stdio.h>
#include <stdlib.h>

#define N	50000

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

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 cc[N + 1]; int d_;

void dfs1(int p1, int i1, int p2, int i2, int d) {
	int o1, o2;

	d_ = max(d_, d);
	for (o1 = eo[i1]; o1--; ) {
		int j1 = ej[i1][o1];

		for (o2 = eo[i2]; o2--; ) {
			int j2 = ej[i2][o2];

			if (j1 != p1 && j2 != p2 && (i1 != i2 || j1 < j2) && cc[j1] == cc[j2])
				dfs1(i1, j1, i2, j2, d + 2);
		}
	}
}

int pp[N], dd[N];

void dfs2(int p, int i, int d) {
	int o;

	pp[i] = p, dd[i] = d;
	for (o = eo[i]; o--; ) {
		int j = ej[i][o];

		if (j != p)
			dfs2(i, j, d + 1);
	}
}

int manacher(char *cc, int n) {
	static char cc_[N * 2 + 2];
	static int rr[N * 2 + 1];
	int i, o, x, ans;

	for (i = 0; i < n * 2 + 1; i++)
		cc_[i] = i % 2 == 0 ? ' ' : cc[i / 2];
	for (i = 0, o = 0, x = 0; i < n * 2 + 1; i++)
		if (i < x && i + rr[o + o - i] < x)
			rr[i] = rr[o + o - i];
		else {
			o = i, x = max(x, i);
			while (x < n * 2 + 1 && o + o - x >= 0 && cc_[x] == cc_[o + o - x])
				x++;
			rr[i] = x - o;
		}
	ans = 0;
	for (i = 0; i < n * 2 + 1; i++)
		ans = max(ans, rr[i] - 1);
	return ans;
}

int main() {
	static int ii[N - 1], jj[N - 1], qu[N], qu1[N], qu2[N];
	static char cc_[N + 1];
	int n, h, h_, h1, h2, i, j, cnt, cnt1, cnt2;

	scanf("%d%s", &n, cc);
	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--;
		ii[h] = i, jj[h] = j;
		append(i, j), append(j, i);
	}
	if (n <= 3000) {
		for (i = 0; i < n; i++)
			dfs1(-1, i, -1, i, 1);
		for (h = 0; h < n - 1; h++)
			if (cc[ii[h]] == cc[jj[h]])
				dfs1(ii[h], jj[h], jj[h], ii[h], 2);
	} else {
		dfs2(-1, 0, 0);
		cnt = 0;
		for (i = 0; i < n; i++)
			if (eo[i] == 1)
				qu[cnt++] = i;
		for (h = 0; h < cnt; h++)
			for (h_ = h + 1; h_ < cnt; h_++) {
				i = qu[h], j = qu[h_];
				cnt1 = 0, cnt2 = 0;
				while (i != j)
					if (dd[i] > dd[j])
						qu1[cnt1++] = i, i = pp[i];
					else
						qu2[cnt2++] = j, j = pp[j];
				for (h1 = 0; h1 < cnt1; h1++)
					cc_[h1] = cc[qu1[h1]];
				cc_[cnt1] = cc[i];
				for (h2 = 0; h2 < cnt2; h2++)
					cc_[cnt1 + cnt2 - h2] = cc[qu2[h2]];
				cc_[cnt1 + 1 + cnt2] = 0;
				d_ = max(d_, manacher(cc_, cnt1 + 1 + cnt2));
			}
	}
	printf("%d\n", d_);
	return 0;
}

Compilation message

lampice.c: In function 'append':
lampice.c:13:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   13 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
lampice.c: In function 'main':
lampice.c:77:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   77 |  scanf("%d%s", &n, cc);
      |  ^~~~~~~~~~~~~~~~~~~~~
lampice.c:81:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |   scanf("%d%d", &i, &j), i--, j--;
      |   ^~~~~~~~~~~~~~~~~~~~~

Subtask #1
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 3 ms 332 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 6996 KB Output is correct
2 Correct 20 ms 7148 KB Output is correct
3 Correct 17 ms 7240 KB Output is correct
4 Correct 18 ms 7576 KB Output is correct
5 Correct 25 ms 7876 KB Output is correct
6 Correct 19 ms 7884 KB Output is correct

Subtask #3
31.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 557 ms 4576 KB Output is correct
2 Correct 420 ms 4276 KB Output is correct
3 Correct 926 ms 4588 KB Output is correct
4 Correct 512 ms 4704 KB Output is correct
5 Correct 369 ms 4444 KB Output is correct
6 Correct 405 ms 4296 KB Output is correct

Subtask #4
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 3 ms 332 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 17 ms 6996 KB Output is correct
9 Correct 20 ms 7148 KB Output is correct
10 Correct 17 ms 7240 KB Output is correct
11 Correct 18 ms 7576 KB Output is correct
12 Correct 25 ms 7876 KB Output is correct
13 Correct 19 ms 7884 KB Output is correct
14 Correct 557 ms 4576 KB Output is correct
15 Correct 420 ms 4276 KB Output is correct
16 Correct 926 ms 4588 KB Output is correct
17 Correct 512 ms 4704 KB Output is correct
18 Correct 369 ms 4444 KB Output is correct
19 Correct 405 ms 4296 KB Output is correct
20 Execution timed out 5037 ms 3752 KB Time limit exceeded
21 Halted 0 ms 0 KB -