Submission #45120

#	Time	Username	Problem	Language	Result	Execution time	Memory
45120		model_code	Shell (info1cup18_shell)	C++17	100 / 100	439 ms	35248 KiB

shell

#include <cstdio>
#include <algorithm>
#include <vector>
#include <cassert>

#define MOD 1000000007LL

using namespace std;

int n, m, p;
vector <int> g[1000010];
int dp[1000010], v[1000010];
long long nr[1000010];

void dfs (int nod)
{
    if (nod == n)
    {
        dp[nod] = 1;
        nr[nod] = 1LL;

        if (nod == v[ p - dp[nod] + 1 ]) ++dp[nod];
        return;
    }

    for (auto &it : g[nod])
    {
        if (dp[it] == 0) dfs (it);

        if (dp[it] > dp[nod]) dp[nod] = dp[it], nr[nod] = nr[it];
        else if (dp[it] == dp[nod]) nr[nod] += nr[it];

        nr[nod] %= MOD;
    }

    if (nod == v[ p - dp[nod] + 1 ]) ++dp[nod];
}

int main ()
{
  //  freopen ("input", "r", stdin);
  //  freopen ("output1", "w", stdout);

    scanf ("%d %d %d", &n, &m, &p);

    assert (1 <= n && n <= 1000000);
  //  assert (1 <= m && m <= 1000000);
    assert (1 <= p && p <= 1000000);

    for (int i = 1; i <= p; ++i)
    {
        scanf ("%d", &v[i]);
        assert (1 <= v[i] && v[i] <= n);
    }

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

        assert (1 <= x && x <= n);
        assert (1 <= y && y <= n);
        assert (x != y);

        g[x].push_back (y);
    }

    dfs (1);

    printf ("%lld\n", nr[1]);

    return 0;
}

Compilation message (stderr)

shell.cpp: In function 'int main()':
shell.cpp:44:11: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf ("%d %d %d", &n, &m, &p);
     ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
shell.cpp:52:15: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf ("%d", &v[i]);
         ~~~~~~^~~~~~~~~~~~~
shell.cpp:59:15: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf ("%d %d", &x, &y);
         ~~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 45 / 45
• Subtask 3: 20 / 20
• Subtask 4: 25 / 25