Submission #680410

#	Time	Username	Problem	Language	Result	Execution time	Memory
680410		rainboy	Wild Boar (JOI18_wild_boar)	C11	62 / 100	4006 ms	189380 KiB

wild_boar

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

#define N	2000
#define M	2000
#define L	100000
#define INF	0x3f3f3f3f3f3f3f3fLL

long long min(long long a, long long b) { return a < b ? a : b; }

int ij[M * 2], cc[M], m;
int *eh[N], eo[N], n;

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

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

long long *dd_; int iq[M * 2 + 1], pq[M * 2], cnt;

int lt(int i, int j) { return dd_[i] < dd_[j]; }

int p2(int p) {
	return (p *= 2) > cnt ? 0 : (p < cnt && lt(iq[p + 1], iq[p]) ? p + 1 : p);
}

void pq_up(int i) {
	int p, q, j;

	for (p = pq[i]; (q = p / 2) && lt(i, j = iq[q]); p = q)
		iq[pq[j] = p] = j;
	iq[pq[i] = p] = i;
}

void pq_dn(int i) {
	int p, q, j;

	for (p = pq[i]; (q = p2(p)) && lt(j = iq[q], i); p = q)
		iq[pq[j] = p] = j;
	iq[pq[i] = p] = i;
}

void pq_add_last(int i) {
	iq[pq[i] = ++cnt] = i;
}

int pq_remove_first() {
	int i = iq[1], j = iq[cnt--];

	if (j != i)
		pq[j] = 1, pq_dn(j);
	pq[i] = 0;
	return i;
}

void solve(long long *dd, int u) {
	static int kk[N];
	int h, i, o;

	memset(dd, 0x3f, m * 2 * sizeof *dd), memset(kk, 0, n * sizeof *kk);
	dd_ = dd, dd[u] = cc[u >> 1], pq_add_last(u);
	while (cnt) {
		h = pq_remove_first(), i = ij[h ^ 1];
		if (kk[i] < 2) {
			kk[i]++;
			for (o = eo[i]; o--; ) {
				int h_ = eh[i][o];
				long long d = dd[h] + cc[h_ >> 1];

				if ((h ^ h_) != 1 && dd[h_] > d) {
					if (dd[h_] == INF)
						pq_add_last(h_);
					dd[h_] = d, pq_up(h_);
				}
			}
		}
	}
}

int main() {
	static long long dd[M * 2][M * 2], dp[M * 2], dq[M * 2];
	static int uu1[M * 2][N], uu2[M * 2][N], ii[L];
	int q, l, g, h, i, j, t, t1, t2, u, v;
	long long ans;

	scanf("%d%d%d%d", &n, &m, &q, &l);
	for (i = 0; i < n; i++)
		eh[i] = (int *) malloc(2 * sizeof *eh[i]);
	for (h = 0; h < m; h++) {
		scanf("%d%d%d", &i, &j, &cc[h]), i--, j--;
		ij[h << 1 | 0] = i, ij[h << 1 | 1] = j;
		append(i, h << 1 | 0), append(j, h << 1 | 1);
	}
	for (u = 0; u < m * 2; u++)
		solve(dd[u], u);
	for (g = 0; g < l; g++)
		scanf("%d", &ii[g]), ii[g]--;
	while (q--) {
		scanf("%d%d", &g, &i), g--, i--;
		ii[g] = i;
	}
	for (v = 0; v < m * 2; v++) {
		memset(uu1[v], -1, n * sizeof *uu1[v]), memset(uu2[v], -1, n * sizeof *uu2[v]);
		for (u = 0; u < m * 2; u++)
			if (dd[u][v] != INF) {
				i = ij[u];
				if (uu1[v][i] == -1 || dd[uu1[v][i]][v] > dd[u][v])
					uu2[v][i] = uu1[v][i], uu1[v][i] = u;
				else if (uu2[v][i] == -1 || dd[uu2[v][i]][v] > dd[u][v])
					uu2[v][i] = u;
			}
	}
	for (g = 0; g + 1 < l; g++) {
		i = ii[g], j = ii[g + 1];
		memset(dq, 0x3f, m * 2 * sizeof *dq);
		t1 = t2 = -1;
		for (t = 0; t < m * 2; t++)
			if (dp[t] != INF) {
				if (t1 == -1 || dp[t1] > dp[t])
					t2 = t1, t1 = t;
				else if (t2 == -1 || dp[t2] > dp[t])
					t2 = t;
			}
		for (v = 0; v < m * 2; v++)
			if (ij[v ^ 1] == j && (u = uu1[v][i]) != -1) {
				if (g == 0)
					dq[v] = min(dq[v], dd[u][v]);
				else {
					if (t1 != -1 && (t1 ^ u) != 1)
						dq[v] = min(dq[v], dp[t1] + dd[u][v]);
					else if (t2 != -1)
						dq[v] = min(dq[v], dp[t2] + dd[u][v]);
					if ((u = uu2[v][i]) != -1) {
						if (t1 != -1 && (t1 ^ u) != 1)
							dq[v] = min(dq[v], dp[t1] + dd[u][v]);
						else if (t2 != -1)
							dq[v] = min(dq[v], dp[t2] + dd[u][v]);
					}
				}
			}
		memcpy(dp, dq, m * 2 * sizeof *dq);
	}
	ans = INF;
	for (v = 0; v < m * 2; v++)
		ans = min(ans, dp[v]);
	printf("%lld\n", ans == INF ? -1 : ans);
	return 0;
}

Compilation message (stderr)

wild_boar.c: In function 'append':
wild_boar.c:18:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   18 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
wild_boar.c: In function 'main':
wild_boar.c:90:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |  scanf("%d%d%d%d", &n, &m, &q, &l);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
wild_boar.c:94:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |   scanf("%d%d%d", &i, &j, &cc[h]), i--, j--;
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
wild_boar.c:101:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  101 |   scanf("%d", &ii[g]), ii[g]--;
      |   ^~~~~~~~~~~~~~~~~~~
wild_boar.c:103:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  103 |   scanf("%d%d", &g, &i), g--, i--;
      |   ^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 35 / 35
• Subtask 3: 15 / 15
• Subtask 4: 0 / 38