Submission #674121

#	Time	Username	Problem	Language	Result	Execution time	Memory
674121		QwertyPi	Shell (info1cup18_shell)	C++14	0 / 100	13 ms	24020 KiB

shell

#include <bits/stdc++.h>
#define int long long
#define fi first
#define se second
using namespace std;

const int MOD = 1e9 + 7;
const int MAXN = 1e6 + 11;
vector<int> G[MAXN];
bool vis[MAXN];
bool zero = true;
vector<int> tp;
int n, m, p;
void dfs(int v){
	vis[v] = true;
	if(v == n) zero = false;
	for(auto i : G[v]){
		if(!vis[i]) dfs(i);
	}
	tp.push_back(v);
}

int dp[MAXN], to[MAXN];

int32_t main(){
	cin.tie(0); cout.tie(0)->sync_with_stdio(false);
	cin >> n >> m >> p;
	vector<int> v;
	for(int i = 0; i < p; i++){
		int k; cin >> k; if(k == 1) continue; v.push_back(k);
	}
	vector<pair<int, int>> vp, vp2;
	for(int i = 0; i < m; i++){
		int u, v; cin >> u >> v;
		vp.push_back({u, v});
		G[u].push_back(v);
	}
	dfs(1);
	reverse(tp.begin(), tp.end());
	// for(auto i : tp) cout << i << ' '; cout << endl;
	while(tp.size() && tp.back() != n) tp.pop_back();
	if(zero || tp.empty()) { cout << 0 << endl; return 0; }
	for(int i = 0; i < tp.size(); i++){
		to[tp[i]] = i + 1;
	}
	vector<int> d; d.push_back(0); d.push_back(1);
	for(int i = 0; i < p; i++){
		if(to[v[i]] == 0){
			cout << 0 << endl; return 0;
		}
		if(i != 0 && to[v[i - 1]] > to[v[i]]){
			cout << 0 << endl; return 0;
		}
		d.push_back(to[v[i]]);
	}
	for(auto i : vp){
		if(to[i.fi] == 0 || to[i.se] == 0) continue;
		int f = to[i.fi], t = to[i.se];
		if(t > *upper_bound(d.begin(), d.end(), f)) continue;
		vp2.push_back({f, t});
		// cout << f << " -> " << t << endl;
	}
	sort(vp2.begin(), vp2.end());
	dp[1] = 1;
	for(auto i : vp2){
		dp[i.se] = (dp[i.fi] + dp[i.se]) % MOD;
	}
	cout << dp[(int) tp.size() - 1] << endl;
}

Compilation message (stderr)

shell.cpp: In function 'int32_t main()':
shell.cpp:43:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |  for(int i = 0; i < tp.size(); i++){
      |                 ~~^~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 45
• Subtask 3: 0 / 20
• Subtask 4: 0 / 25