Submission #122905

#	Time	Username	Problem	Language	Result	Execution time	Memory
122905		miguel	Paths (BOI18_paths)	C++14	100 / 100	570 ms	100484 KiB

paths

#include<bits/stdc++.h>
using namespace std;
#define rc(x) return cout<<x<<endl,0
#define pb push_back
#define dbg(x) cout << #x << '=' << x << '\n';
#define ll long long
#define sz size()
#define x first
#define y second
#define pi pair <int, int>
#define pii pair <pi, int>
#define vi vector <int>
const ll mod = 1000000007;
#define int ll
int n, m, k, c[300001], dp[300001][32];
vector <int> g[300001];

int gcd(int a, int b){
    if(a==0) return b;
    else return gcd(b%a, a);
}

int32_t main(){
    ios_base :: sync_with_stdio(0); cin.tie(); cout.tie();
    cin>>n>>m>>k;
    for(int i=1; i<=n; i++){
        cin>>c[i];
        c[i]--;
    }
    for(int i=1; i<=m; i++){
        int x, y;
        cin>>x>>y;
        g[x].pb(y);
        g[y].pb(x);
    }
    for(int i=1; i<=n; i++) dp[i][(1<<c[i])]=1;
    for(int mask=1; mask<(1<<k); mask++){
        for(int i=1; i<=n; i++){
            if(dp[i][mask]==0) continue;
            for(int j: g[i]){
                if(((1<<c[j])&mask)) continue;
                else dp[j][(mask|(1<<c[j]))]+=dp[i][mask];
            }
        }
    }
    int ans=0;
    for(int mask=1; mask<(1<<k); mask++){
        for(int i=1; i<=n; i++){
            //if(dp[i][mask]) cout<<i<<" "<<mask<<" "<<dp[i][mask]<<endl;
            ans+=dp[i][mask];
        }
    }
    cout<<ans-n;
}

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