Submission #106158

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
106158	2019-04-16T22:51:52 Z	luciocf	Pipes (BOI13_pipes)	C++14	74.0741 / 100	344 ms	38264 KB

pipes

#include <bits/stdc++.h>

using namespace std;

const int maxn = 1e5+10;
const int maxm = 5e5+10;
const int maxl = 20;
const int inf = 2e9+10;

struct T
{
	int x, mx, mi;
} tab[maxn][maxl];

typedef pair<int, int> pii;

int a[maxn], cur[maxn];
pii E[maxm];

int edge[maxn], costEdge[maxm];

int pai[maxn], nivel[maxn];

bool mark[maxn];

vector<pii> grafo[maxn];

void dfs(int u, int p)
{
	mark[u] = 1;

	for (auto pp: grafo[u])
	{
		int v = pp.first, e = pp.second;
		if (mark[v]) continue;

		edge[v] = e;
		pai[v] = u, nivel[v] = nivel[u]+1;

		dfs(v, u);

		cur[u] += costEdge[e]/2;
	}

	if (u != 1)
	{
		costEdge[edge[u]] = 2*(a[u]-cur[u]);
		cur[u] = a[u];
	}
}

void build(int n)
{
	for (int i = 1; i <= n; i++)
	{
		tab[i][0].x = pai[i];
		tab[i][0].mx = tab[i][0].mi = costEdge[edge[i]];
	}

	for (int j = 1; j < maxl; j++)
	{
		for (int i = 1; i <= n; i++)
		{
			tab[i][j].x = tab[tab[i][j-1].x][j-1].x;
			tab[i][j].mx = max(tab[i][j-1].mx, tab[tab[i][j-1].x][j-1].mx);
			tab[i][j].mi = max(tab[i][j-1].mi, tab[tab[i][j-1].x][j-1].mi);
		}
	}
}

int lca(int u, int v)
{
	if (nivel[u] < nivel[v]) swap(u, v);

	for (int i = maxl-1; i >= 0; i--)
		if (nivel[u]-(1<<i) >= nivel[v])
			u = tab[u][i].x;

	if (u == v) return u;

	for (int i = maxl-1; i >= 0; i--)
		if (tab[u][i].x && tab[v][i].x && tab[u][i].x != tab[v][i].x)
			u = tab[u][i].x, v = tab[v][i].x;

	return pai[u];
}

pii get(int u, int l)
{
	int mx = -inf, mi = inf;

	for (int i = maxl-1; i >= 0; i--)
	{
		if (nivel[u]-(1<<i) >= nivel[l])
		{
			mx = max(mx, tab[u][i].mx);
			mi = min(mi, tab[u][i].mi);
			u = tab[u][i].x;
		}
	}

	return {mx, mi};
}

int main(void)
{
	int n, m;
	scanf("%d %d", &n, &m);

	for (int i = 1; i <= n; i++)
		scanf("%d", &a[i]);

	for (int i = 1; i <= m; i++)
	{
		int u, v;
		scanf("%d %d", &u, &v);

		grafo[u].push_back({v, i});
		grafo[v].push_back({u, i});

		E[i] = {u, v};
	}

	memset(costEdge, -1, sizeof costEdge);

	dfs(1, 0);

	if (cur[1] != a[1])
	{
		printf("0\n");
		return 0;
	}

	build(n);

	bool ok = 1;

	for (int i = 1; i <= m; i++)
	{
		if (costEdge[i] == -1)
		{
			int u = E[i].first, v = E[i].second;

			int low = lca(u, v), mx = -inf, mi = inf;

			pii ans = get(u, low);
			mx = max(mx, ans.first); mi = min(mi, ans.second);

			ans = get(v, low);
			mx = max(mx, ans.first); mi = min(mi, ans.second);

			if (mx != 0 || mi != 0)
			{
				ok = 0;
				break;
			}
		}
	}

	if (!ok) printf("0\n");
	else
	{
		for (int i = 1; i <= m; i++)
		{
			if (costEdge[i] == -1) printf("0\n");
			else printf("%d\n", costEdge[i]);
		}
	}
}

Compilation message

pipes.cpp: In function 'int main()':
pipes.cpp:108:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~~
pipes.cpp:111:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a[i]);
   ~~~~~^~~~~~~~~~~~~
pipes.cpp:116:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &u, &v);
   ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1

30.0 / 30.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	5 ms	4736 KB	Output is correct
2	Correct	5 ms	4736 KB	Output is correct
3	Correct	6 ms	4992 KB	Output is correct
4	Correct	147 ms	34936 KB	Output is correct
5	Correct	5 ms	4736 KB	Output is correct
6	Correct	5 ms	4736 KB	Output is correct
7	Correct	6 ms	4736 KB	Output is correct
8	Correct	6 ms	4784 KB	Output is correct
9	Correct	8 ms	4992 KB	Output is correct
10	Correct	6 ms	4992 KB	Output is correct
11	Correct	7 ms	4992 KB	Output is correct
12	Correct	7 ms	4992 KB	Output is correct
13	Correct	120 ms	28920 KB	Output is correct
14	Correct	121 ms	33400 KB	Output is correct
15	Correct	180 ms	35192 KB	Output is correct
16	Correct	291 ms	30576 KB	Output is correct
17	Correct	236 ms	35020 KB	Output is correct
18	Correct	173 ms	35192 KB	Output is correct
19	Correct	222 ms	36940 KB	Output is correct
20	Correct	16 ms	4608 KB	Output is correct
21	Correct	7 ms	4992 KB	Output is correct
22	Correct	170 ms	35200 KB	Output is correct
23	Correct	127 ms	28792 KB	Output is correct
24	Correct	191 ms	35164 KB	Output is correct
25	Correct	169 ms	30072 KB	Output is correct

Subtask #2

44.0740740741 / 70.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	6 ms	4608 KB	Output isn't correct
2	Incorrect	6 ms	4736 KB	Output isn't correct
3	Correct	186 ms	34884 KB	Output is correct
4	Correct	107 ms	14396 KB	Output is correct
5	Correct	116 ms	11072 KB	Output is correct
6	Correct	344 ms	28456 KB	Output is correct
7	Incorrect	7 ms	4736 KB	Output isn't correct
8	Incorrect	6 ms	4736 KB	Output isn't correct
9	Correct	6 ms	4736 KB	Output is correct
10	Correct	6 ms	4608 KB	Output is correct
11	Correct	6 ms	4736 KB	Output is correct
12	Correct	6 ms	4736 KB	Output is correct
13	Correct	6 ms	4736 KB	Output is correct
14	Incorrect	6 ms	4736 KB	Output isn't correct
15	Incorrect	6 ms	4736 KB	Output isn't correct
16	Incorrect	6 ms	4736 KB	Output isn't correct
17	Correct	6 ms	4992 KB	Output is correct
18	Correct	6 ms	4736 KB	Output is correct
19	Correct	6 ms	4736 KB	Output is correct
20	Correct	6 ms	4736 KB	Output is correct
21	Correct	7 ms	4864 KB	Output is correct
22	Incorrect	6 ms	4736 KB	Output isn't correct
23	Incorrect	85 ms	12228 KB	Output isn't correct
24	Incorrect	92 ms	13432 KB	Output isn't correct
25	Correct	198 ms	34888 KB	Output is correct
26	Correct	141 ms	13816 KB	Output is correct
27	Correct	107 ms	14048 KB	Output is correct
28	Correct	140 ms	11188 KB	Output is correct
29	Correct	288 ms	24796 KB	Output is correct
30	Incorrect	108 ms	14712 KB	Output isn't correct
31	Incorrect	100 ms	14840 KB	Output isn't correct
32	Incorrect	103 ms	11900 KB	Output isn't correct
33	Correct	199 ms	36908 KB	Output is correct
34	Correct	103 ms	13480 KB	Output is correct
35	Correct	107 ms	14328 KB	Output is correct
36	Correct	100 ms	11196 KB	Output is correct
37	Correct	335 ms	28448 KB	Output is correct
38	Incorrect	94 ms	14456 KB	Output isn't correct
39	Incorrect	108 ms	11676 KB	Output isn't correct
40	Incorrect	100 ms	13176 KB	Output isn't correct
41	Correct	175 ms	38264 KB	Output is correct
42	Correct	88 ms	13560 KB	Output is correct
43	Correct	99 ms	14492 KB	Output is correct
44	Correct	79 ms	11128 KB	Output is correct
45	Correct	238 ms	23700 KB	Output is correct
46	Incorrect	141 ms	15096 KB	Output isn't correct
47	Incorrect	111 ms	13204 KB	Output isn't correct
48	Incorrect	113 ms	14636 KB	Output isn't correct
49	Correct	182 ms	33548 KB	Output is correct
50	Correct	102 ms	13432 KB	Output is correct
51	Correct	93 ms	12456 KB	Output is correct
52	Correct	130 ms	11896 KB	Output is correct
53	Correct	275 ms	24440 KB	Output is correct
54	Incorrect	103 ms	13916 KB	Output isn't correct