Submission #171669

#	Time	Username	Problem	Language	Result	Execution time	Memory
171669		alishahali1382	Paths (BOI18_paths)	C++14	100 / 100	519 ms	32008 KiB

paths

#include <bits/stdc++.h>
#pragma GCC optimize ("O2")
#pragma GCC optimize ("unroll-loops")
//#pragma GCC optimize("no-stack-protector,fast-math")

using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef pair<ll, ll> pll;
#define debug(x) cerr<<#x<<'='<<(x)<<endl;
#define debugp(x) cerr<<#x<<"= {"<<(x.first)<<", "<<(x.second)<<"}"<<endl;
#define debug2(x, y) cerr<<"{"<<#x<<", "<<#y<<"} = {"<<(x)<<", "<<(y)<<"}"<<endl;
#define debugv(v) cerr<<#v<<" : ";for (auto x:v) cerr<<x<<' ';cerr<<endl;
#define all(x) x.begin(), x.end()
#define pb push_back
#define kill(x) return cout<<x<<'\n', 0;

const ld eps=1e-7;
const int inf=1000000010;
const ll INF=10000000000000010LL;
const int mod = 1000000007;
const int MAXN = 300010, LOG=20;

ll n, m, k, u, v, x, y, t, a, b, ans;
ll dp[6][MAXN];
int col[MAXN];
vector<int> G[MAXN], vec[6];
bool mark[6];

void bt(int last, int lv){
	lv++;
	for (int c=1; c<=k; c++) if (!mark[c]){
		mark[c]=1;
		memset(dp[lv], 0, sizeof(dp[lv]));
		for (int v:vec[c]){
			for (int u:G[v]) if (col[u]==last) dp[lv][v]+=dp[lv-1][u];
			ans+=dp[lv][v];
		}
		bt(c, lv);
		mark[c]=0;
	}
}

int main(){
	ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	//freopen("input.txt", "r", stdin);
	//freopen("output.txt", "w", stdout);
	cin>>n>>m>>k;
	for (int i=1; i<=n; i++) cin>>col[i], vec[col[i]].pb(i);
	while (m--){
		cin>>u>>v;
		G[u].pb(v);
		G[v].pb(u);
	}
	for (int i=1; i<=k; i++){
		mark[i]=1;
		for (int v:vec[i]) dp[1][v]=1;
		bt(i, 1);
		mark[i]=0;
	}
	cout<<ans<<'\n';
	
	return 0;
}

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