Submission #448548

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
448548	2021-07-30T13:33:30 Z	rainboy	Rima (COCI17_rima)	C	126 / 140	1000 ms	65556 KB

rima

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define N	500000
#define L	3000000

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

unsigned int X = 12345;

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

char *ss[N * 2];

int compare(int i, int j) {
	int c = strcmp(ss[i], ss[j]);

	return c == 0 ? i - j : c;
}

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) {
			int c = compare(ii[j], i_);

			if (c == 0)
				j++;
			else if (c < 0) {
				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 *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;
}

int dp[N];

void dfs(int i) {
	int o;

	for (o = eo[i]; o--; ) {
		int j = ej[i][o];

		dfs(j);
		dp[i] = max(dp[i], dp[j] - 1);
	}
	dp[i] += 1 + eo[i];
}

int main() {
	static int ii[N * 2];
	static char root[N];
	int n, i, j, ans;

	scanf("%d", &n);
	for (i = 0; i < n; i++) {
		static char s[L + 1];
		int l, h1, h2;
		char tmp;

		scanf("%s", s), l = strlen(s);
		for (h1 = 0, h2 = l - 1; h1 < h2; h1++, h2--)
			tmp = s[h1], s[h1] = s[h2], s[h2] = tmp;
		ss[i] = strdup(s);
		s[l - 1] = 0;
		ss[n + i] = strdup(s);
	}
	for (i = 0; i < n * 2; i++)
		ii[i] = i;
	sort(ii, 0, n * 2);
	for (i = 0; i < n; i++)
		ej[i] = (int *) malloc(2 * sizeof *ej[i]);
	for (i = 0, j = 0; j < n * 2; i = j) {
		j = i + 1;
		if (ii[i] >= n)
			root[ii[i] - n] = 1;
		while (j < n * 2 && strcmp(ss[ii[i]], ss[ii[j]]) == 0) {
			if (ii[i] < n)
				append(ii[i], ii[j] - n);
			else
				root[ii[j] - n] = 1;
			j++;
		}
	}
	for (i = 0; i < n; i++)
		if (root[i])
			dfs(i);
	ans = 0;
	for (i = 0, j = 0; j < n * 2; i = j) {
		int mx1, mx2;

		j = i;
		if (ii[j] < n)
			j++;
		mx1 = mx2 = 0;
		while (j < n * 2 && strcmp(ss[ii[i]], ss[ii[j]]) == 0) {
			int j_ = ii[j++] - n;

			if (mx1 < dp[j_] - 1)
				mx2 = mx1, mx1 = dp[j_] - 1;
			else if (mx2 < dp[j_] - 1)
				mx2 = dp[j_] - 1;
		}
		ans = max(ans, j - i + mx1 + mx2);
	}
	printf("%d\n", ans);
	return 0;
}

Compilation message

rima.c: In function 'append':
rima.c:51:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   51 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
rima.c: In function 'main':
rima.c:75:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
rima.c:81:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |   scanf("%s", s), l = strlen(s);
      |   ^~~~~~~~~~~~~~

Subtask #1

126.0 / 140.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	332 KB	Output is correct
2	Correct	0 ms	332 KB	Output is correct
3	Correct	0 ms	332 KB	Output is correct
4	Execution timed out	1094 ms	65556 KB	Time limit exceeded
5	Correct	30 ms	6108 KB	Output is correct
6	Correct	9 ms	1996 KB	Output is correct
7	Correct	7 ms	1704 KB	Output is correct
8	Correct	5 ms	1484 KB	Output is correct
9	Correct	70 ms	8052 KB	Output is correct
10	Correct	5 ms	1612 KB	Output is correct