Submission #1193361

#	Time	Username	Problem	Language	Result	Execution time	Memory
1193361		SSSM	Paths (BOI18_paths)	C++20	100 / 100	264 ms	37568 KiB

paths

#include <bits/stdc++.h>

/*
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC target ("avx2")
*/

using namespace std;

/*
#include <ext/pb_ds/assoc_container.hpp> 
#include <ext/pb_ds/tree_policy.hpp> 
using namespace __gnu_pbds;
template<class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
*/

#define F first
#define S second
#define pb push_back
#define FIO freopen("input.txt", "r", stdin);freopen("output.txt", "w", stdout)
#define md(a) ((a%mod+mod)%mod)
#define all(a) a.begin(), a.end()
#define MP make_pair
#define lc (id<<1)
#define rc (lc|1)
#define mid (l+r)/2
#define kill(a) cout << a << "\n", exit(0)
#define SZ(a) (ll)a.size()
typedef pair<int,int> pii;
typedef pair<long long ,long long> pll;
typedef long long ll;
typedef long double ld;
typedef vector<vector<ll>> matrix;
mt19937_64  rng(chrono::steady_clock::now().time_since_epoch().count());

ll const maxn=3e5+10, mod=1e9+7, INF=1e18, LOG=20, sq=65;

ll poww(ll a, ll b, ll mod) {
 if (b == 0) return 1;
 return 1 * poww(1 * a * a % mod, b / 2, mod) * ((b % 2 == 1) ? a : 1) % mod;
}

ll n, m, k, ans, dp[maxn][6], col[maxn];
vector<ll> ver[6], g[maxn];
bool mark[6];

void bt(ll lst, ll len)
{
	len++;
	for(ll c=1;c<=k;c++) if(!mark[c]){
		mark[c]=1;
		for(ll i=1;i<=n;i++) dp[i][len]=0;
		for(ll v:ver[c]) {
			for(ll u:g[v]) if(col[u]==lst){ 
				dp[v][len]+=dp[u][len-1];
			}
			ans+=dp[v][len];
		}
		
		bt(c, len);
		mark[c]=0;
	}
}

int main()
{
	ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);

	cin>>n>>m>>k;
	for(ll i=1;i<=n;i++){
		cin>>col[i];
		ver[col[i]].pb(i);
	}
	for(ll i=1;i<=m;i++)
	{
		ll v, u;
		cin>>v>>u;
		g[v].pb(u);
		g[u].pb(v);
	}

	for(ll i=1;i<=k;i++)
	{
		mark[i]=1;
		for(ll v:ver[i]) dp[v][1]=1;
		bt(i, 1);
		mark[i]=0;
	}
	cout<<ans<<"\n";
}

• Subtask 1: 23 / 23
• Subtask 2: 20 / 20
• Subtask 3: 27 / 27
• Subtask 4: 30 / 30