Submission #106160

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
106160	2019-04-16T23:01:29 Z	luciocf	Pipes (BOI13_pipes)	C++14	74.0741 / 100	361 ms	38308 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 = min(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	6 ms	4736 KB	Output is correct
2	Correct	6 ms	4736 KB	Output is correct
3	Correct	7 ms	4992 KB	Output is correct
4	Correct	199 ms	35092 KB	Output is correct
5	Correct	5 ms	4608 KB	Output is correct
6	Correct	5 ms	4736 KB	Output is correct
7	Correct	6 ms	4736 KB	Output is correct
8	Correct	7 ms	4736 KB	Output is correct
9	Correct	7 ms	4992 KB	Output is correct
10	Correct	6 ms	4992 KB	Output is correct
11	Correct	8 ms	4992 KB	Output is correct
12	Correct	8 ms	4992 KB	Output is correct
13	Correct	125 ms	28892 KB	Output is correct
14	Correct	167 ms	33412 KB	Output is correct
15	Correct	202 ms	35196 KB	Output is correct
16	Correct	138 ms	30556 KB	Output is correct
17	Correct	201 ms	35116 KB	Output is correct
18	Correct	176 ms	35200 KB	Output is correct
19	Correct	177 ms	36856 KB	Output is correct
20	Correct	6 ms	4736 KB	Output is correct
21	Correct	6 ms	4992 KB	Output is correct
22	Correct	235 ms	35192 KB	Output is correct
23	Correct	125 ms	28792 KB	Output is correct
24	Correct	163 ms	35172 KB	Output is correct
25	Correct	122 ms	30080 KB	Output is correct

Subtask #2

44.0740740741 / 70.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	6 ms	4708 KB	Output isn't correct
2	Incorrect	5 ms	4736 KB	Output isn't correct
3	Correct	125 ms	34808 KB	Output is correct
4	Correct	99 ms	14200 KB	Output is correct
5	Correct	99 ms	11000 KB	Output is correct
6	Correct	361 ms	28436 KB	Output is correct
7	Incorrect	6 ms	4660 KB	Output isn't correct
8	Incorrect	5 ms	4736 KB	Output isn't correct
9	Correct	6 ms	4864 KB	Output is correct
10	Correct	6 ms	4736 KB	Output is correct
11	Correct	7 ms	4608 KB	Output is correct
12	Correct	6 ms	4736 KB	Output is correct
13	Correct	5 ms	4608 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	7 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	7 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	76 ms	12152 KB	Output isn't correct
24	Incorrect	116 ms	13304 KB	Output isn't correct
25	Correct	167 ms	34864 KB	Output is correct
26	Correct	104 ms	13900 KB	Output is correct
27	Correct	106 ms	14072 KB	Output is correct
28	Correct	147 ms	11232 KB	Output is correct
29	Correct	293 ms	24952 KB	Output is correct
30	Incorrect	108 ms	14712 KB	Output isn't correct
31	Incorrect	109 ms	14712 KB	Output isn't correct
32	Incorrect	91 ms	11896 KB	Output isn't correct
33	Correct	247 ms	36984 KB	Output is correct
34	Correct	107 ms	13432 KB	Output is correct
35	Correct	100 ms	14328 KB	Output is correct
36	Correct	102 ms	11128 KB	Output is correct
37	Correct	332 ms	28440 KB	Output is correct
38	Incorrect	104 ms	14328 KB	Output isn't correct
39	Incorrect	84 ms	11640 KB	Output isn't correct
40	Incorrect	115 ms	13304 KB	Output isn't correct
41	Correct	189 ms	38308 KB	Output is correct
42	Correct	99 ms	13732 KB	Output is correct
43	Correct	90 ms	14584 KB	Output is correct
44	Correct	87 ms	11000 KB	Output is correct
45	Correct	239 ms	23644 KB	Output is correct
46	Incorrect	100 ms	15096 KB	Output isn't correct
47	Incorrect	103 ms	13160 KB	Output isn't correct
48	Incorrect	136 ms	14712 KB	Output isn't correct
49	Correct	145 ms	33572 KB	Output is correct
50	Correct	89 ms	13560 KB	Output is correct
51	Correct	88 ms	12408 KB	Output is correct
52	Correct	96 ms	11896 KB	Output is correct
53	Correct	256 ms	24540 KB	Output is correct
54	Incorrect	91 ms	13816 KB	Output isn't correct