Submission #481425

#	Time	Username	Problem	Language	Result	Execution time	Memory
481425		rainboy	Putovanje (COCI20_putovanje)	C11	110 / 110	70 ms	16004 KiB

putovanje

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

#define N	200000

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

int ij[N - 1], aa[N - 1], bb[N - 1];
int *eh[N], eo[N];

void append(int i, int j) {
	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] = j;
}

int pp[N], qq[N], dd[N];

int dfs1(int p, int i, int d) {
	int o, j_, s, k_;

	pp[i] = p, dd[i] = d;
	s = 1, k_ = 0, j_ = -1;
	for (o = eo[i]; o--; ) {
		int h = eh[i][o], j = i ^ ij[h];

		if (j != p) {
			int k = dfs1(i, j, d + 1);

			if (k_ < k)
				k_ = k, j_ = j;
			s += k;
		}
	}
	qq[i] = j_;
	return s;
}

void dfs2(int p, int i, int q) {
	int o, j_;

	j_ = qq[i], qq[i] = q;
	for (o = eo[i]; o--; ) {
		int h = eh[i][o], j = i ^ ij[h];

		if (j != p) {
			dfs2(i, j, j == j_ ? q : j);
		}
	}
}

int lca(int i, int j) {
	while (qq[i] != qq[j])
		if (dd[qq[i]] > dd[qq[j]])
			i = pp[qq[i]];
		else
			j = pp[qq[j]];
	return dd[i] < dd[j] ? i : j;
}

int kk[N]; long long ans;

void dfs3(int p, int i) {
	int o;

	for (o = eo[i]; o--; ) {
		int h = eh[i][o], j = i ^ ij[h];

		if (j != p) {
			dfs3(i, j);
			ans += min((long long) aa[h] * kk[j], bb[h]);
			kk[i] += kk[j];
		}
	}
}

int main() {
	int n, h, i, j;

	scanf("%d", &n);
	for (i = 0; i < n; i++)
		eh[i] = (int *) malloc(2 * sizeof *eh[i]);
	for (h = 0; h < n - 1; h++) {
		scanf("%d%d%d%d", &i, &j, &aa[h], &bb[h]), i--, j--;
		ij[h] = i ^ j;
		append(i, h), append(j, h);
	}
	dfs1(-1, 0, 0);
	dfs2(-1, 0, 0);
	for (i = 0; i + 1 < n; i++)
		kk[i]++, kk[i + 1]++, kk[lca(i, i + 1)] -= 2;
	dfs3(-1, 0);
	printf("%lld\n", ans);
	return 0;
}

Compilation message (stderr)

putovanje.c: In function 'append':
putovanje.c:14:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   14 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
putovanje.c: In function 'main':
putovanje.c:82:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
putovanje.c:86:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   86 |   scanf("%d%d%d%d", &i, &j, &aa[h], &bb[h]), i--, j--;
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 25 / 25
• Subtask 3: 65 / 65