Submission #941007

#	Time	Username	Problem	Language	Result	Execution time	Memory
941007		phoenix0423	Paths (BOI18_paths)	C++17	100 / 100	468 ms	100692 KiB

paths

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pll;
#define fastio ios::sync_with_stdio(false), cin.tie(0)
#define pb push_back
#define eb emplace_back
#define f first
#define s second
#define int long long
#define lowbit(x) x&-x
const int maxn = 3e5 + 5;
vector<int> adj[maxn];
int c[maxn];
int n, m, k;
int dp[maxn][32];

signed main(void){
    fastio;
    cin>>n>>m>>k;
    for(int i = 0; i < n; i++) cin>>c[i], c[i]--;
    for(int i = 0; i < m; i++){
        int a, b;
        cin>>a>>b;
        a--, b--;
        adj[a].pb(b);
        adj[b].pb(a);
    }
    for(int i = 0; i < n; i++) dp[i][(1 << c[i])] = 1;
    int ans = 0;
    for(int rd = 1; rd < k; rd++){
        for(int i = 0; i < n; i++){
            for(int mask = 0; mask < (1 << k); mask++){
                if(__builtin_popcount(mask) != rd) continue;
                if(!dp[i][mask]) continue;
                for(auto x : adj[i]){
                    if(mask & (1 << c[x])) continue;
                    dp[x][mask | (1 << c[x])] += dp[i][mask];
                }
            }
        }
    }
    for(int i = 0; i < n; i++){
        for(int mask = 1; mask < (1 << k); mask++){
            if(__builtin_popcount(mask) == 1) continue;
            ans += dp[i][mask];
        }
    }
    cout<<ans<<"\n";
}

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