Submission #383377

#	Time	Username	Problem	Language	Result	Execution time	Memory
383377		luciocf	Bitaro’s Party (JOI18_bitaro)	C++14	14 / 100	129 ms	21220 KiB

bitaro

#include <bits/stdc++.h>

using namespace std;

const int maxn = 2e5+10;
const int inf = 1e9+10;

int n, m, q;
int dp[maxn];

bool mark[maxn], block[maxn];

vector<int> grafo[2][maxn], ord;

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

	for (auto v: grafo[1][u])
		if (!mark[v])
			dfs(v);

	ord.push_back(u);
}

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

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

		grafo[0][u].push_back(v);
		grafo[1][v].push_back(u);
	}

	int source, m;
	scanf("%d %d", &source, &m);

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

		block[u] = 1;
	}

	dfs(source);

	for (int i = 1; i <= n; i++)
		dp[i] = -inf;

	dp[source] = 0;

	for (int i = (int)ord.size()-2; i >= 0; i--)
	{
		int u = ord[i];

		for (auto v: grafo[0][u])
			dp[u] = max(dp[u], 1 + dp[v]);
	}

	int ans = -inf;

	for (int i = 1; i <= n; i++)
		if (!block[i])
			ans = max(ans, dp[i]);

	if (ans == -inf) printf("-1\n");
	else printf("%d\n", ans);
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:28:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   28 |  scanf("%d %d %d", &n, &m, &q);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:33:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   33 |   scanf("%d %d", &u, &v);
      |   ~~~~~^~~~~~~~~~~~~~~~~
bitaro.cpp:40:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   40 |  scanf("%d %d", &source, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:45:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   45 |   scanf("%d", &u);
      |   ~~~~~^~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 0 / 86