Submission #742215

#	Time	Username	Problem	Language	Result	Execution time	Memory
742215		rainboy	Special graph (IZhO13_specialg)	C11	100 / 100	67 ms	15580 KiB

specialg

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

#define N	100000

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 rr[N], dd[N], ta[N], tb[N]; char visited[N];

void dfs(int i, int r, int d) {
	static int time;
	int o;

	if (visited[i] == 1)
		return;
	visited[i] = 1;
	ta[i] = time++;
	rr[i] = r, dd[i] = d;
	for (o = eo[i]; o--; ) {
		int j = ej[i][o];

		dfs(j, r, d + 1);
	}
	tb[i] = time;
}

int ft[N];

void update(int i, int n, int x) {
	while (i < n) {
		ft[i] += x;
		i |= i + 1;
	}
}

int query(int i) {
	int x = 0;

	while (i >= 0) {
		x += ft[i];
		i &= i + 1, i--;
	}
	return x;
}

int main() {
	static int pp[N];
	int n, m, i, j;

	scanf("%d", &n);
	for (i = 0; i < n; i++)
		ej[i] = (int *) malloc(2 * sizeof *ej[i]);
	for (i = 0; i < n; i++) {
		scanf("%d", &pp[i]), pp[i]--;
		if (pp[i] != -1)
			append(pp[i], i);
	}
	for (i = 0; i < n; i++) {
		if (visited[i])
			continue;
		j = i;
		while (pp[j] != -1 && !visited[j])
			visited[j] = -1, j = pp[j];
		dfs(j, j, 0);
	}
	scanf("%d", &m);
	while (m--) {
		int t, ans;

		scanf("%d", &t);
		if (t == 1) {
			scanf("%d", &i), i--;
			pp[i] = -1;
			update(ta[i], n, 1), update(tb[i], n, -1);
		} else {
			scanf("%d%d", &i, &j), i--, j--;
			if (ta[j] <= ta[i] && tb[i] <= tb[j])
				ans = query(ta[i]) - query(ta[j]) == 0 ? dd[i] - dd[j] : -1;
			else {
				if (query(ta[i]) > 0)
					ans = -1;
				else {
					ans = dd[i] + 1;
					if ((i = pp[rr[i]]) == -1 || ta[i] < ta[j] || ta[i] >= tb[j])
						ans = -1;
					else
						ans = query(ta[i]) - query(ta[j]) == 0 ? ans + dd[i] - dd[j] : -1;
				}
			}
			printf("%d\n", ans);
		}
	}
	return 0;
}

Compilation message (stderr)

specialg.c: In function 'append':
specialg.c:11:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   11 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
specialg.c: In function 'main':
specialg.c:58:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   58 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
specialg.c:62:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |   scanf("%d", &pp[i]), pp[i]--;
      |   ^~~~~~~~~~~~~~~~~~~
specialg.c:74:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |  scanf("%d", &m);
      |  ^~~~~~~~~~~~~~~
specialg.c:78:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |   scanf("%d", &t);
      |   ^~~~~~~~~~~~~~~
specialg.c:80:4: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   80 |    scanf("%d", &i), i--;
      |    ^~~~~~~~~~~~~~~
specialg.c:84:4: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   84 |    scanf("%d%d", &i, &j), i--, j--;
      |    ^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100