Submission #466558

#TimeUsernameProblemLanguageResultExecution timeMemory
466558rainboyRoad Closures (APIO21_roads)C++17
36 / 100
2082 ms10252 KiB
#include "roads.h"
#include <stdlib.h>
#include <vector>

using namespace std;

typedef vector<int> vi;
typedef vector<long long> vl;

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

const int N = 100000;

unsigned int X = 12345;

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

void sort(long long *aa, int l, int r) {
	while (l < r) {
		int i = l, j = l, k = r;
		long long a = aa[l + rand_() % (r - l)], tmp;

		while (j < k)
			if (aa[j] == a)
				j++;
			else if (aa[j] < a) {
				tmp = aa[i], aa[i] = aa[j], aa[j] = tmp;
				i++, j++;
			} else {
				k--;
				tmp = aa[j], aa[j] = aa[k], aa[k] = tmp;
			}
		sort(aa, l, i);
		l = k;
	}
}

int ii[N - 1], jj[N - 1], ww[N - 1];

int *eh[N], eo[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 xx[N], dp[N], dq[N]; int k;

void dfs(int p, int i) {
	int o, m, h;
	long long x;

	x = 0;
	for (o = eo[i]; o--; ) {
		int h = eh[i][o], j = i ^ ii[h] ^ jj[h];

		if (j != p) {
			dfs(i, j);
			x += dp[j];
		}
	}
	m = 0;
	for (o = eo[i]; o--; ) {
		int h = eh[i][o], j = i ^ ii[h] ^ jj[h];

		if (j != p)
			xx[m++] = dq[j] + ww[h] - dp[j];
	}
	sort(xx, 0, m);
	dp[i] = x;
	for (h = m - 1; h >= 0 && h >= m - k && xx[h] > 0; h--)
		dp[i] += xx[h];
	dq[i] = x;
	for (h = m - 1; h >= 0 && h >= m - (k - 1) && xx[h] > 0; h--)
		dq[i] += xx[h];
}

vl minimum_closure_costs(int n, vi ii_, vi jj_, vi ww_) {
	vl ans(n);
	int h, i, star, path;

	for (h = 0; h < n - 1; h++)
		ii[h] = ii_[h], jj[h] = jj_[h], ww[h] = ww_[h];
	star = 1;
	for (h = 0; h < n - 1; h++)
		if (ii[h] != 0) {
			star = 0;
			break;
		}
	path = 1;
	for (h = 0; h < n - 1; h++)
		if (ii[h] != h || jj[h] != h + 1) {
			path = 0;
			break;
		}
	if (star) {
		for (h = 0; h < n - 1; h++)
			xx[h] = ww[h];
		sort(xx, 0, n - 1);
		for (h = n - 1; h >= 0; h--)
			ans[h] = h == n - 1 ? 0 : ans[h + 1] + xx[n - 2 - h];
	} else if (path) {
		long long dp, dq, dp_, dq_;

		for (h = 0; h < n; h++)
			ans[h] = 0;
		for (h = 0; h < n - 1; h++)
			ans[0] += ww[h];
		dp = ww[0], dq = 0;
		for (h = 1; h < n - 1; h++)
			dp_ = dq + ww[h], dq_ = max(dp, dq), dp = dp_, dq = dq_;
		ans[1] = ans[0] - max(dp, dq);
	} else {
		for (i = 0; i < n; i++)
			eh[i] = (int *) malloc(2 * sizeof *eh[i]);
		for (h = 0; h < n - 1; h++)
			append(ii[h], h), append(jj[h], h);
		for (h = 0; h < n - 1; h++)
			ans[0] += ww[h];
		for (k = 1; k < n; k++) {
			dfs(-1, 0);
			ans[k] = ans[0] - dp[0];
		}
	}
	return ans;
}

Compilation message (stderr)

roads.cpp: In function 'void append(int, int)':
roads.cpp:47:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   47 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
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