Submission #645484

#	Time	Username	Problem	Language	Result	Execution time	Memory
645484		mychecksedad	Paths (BOI18_paths)	C++17	100 / 100	640 ms	124132 KiB

paths

/* Author : Mychecksdead */
#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define PI 3.1415926535
#define pb push_back
#define setp() cout << setprecision(15)
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " is " << x << '\n';
const int N = 1e6+100, M = 1e5+10, F = 2147483646, K = 20;



int n, m, k, a[N];
ll ans = 0, dp[N][32];
vector<int> g[N];
vector<bool> vis(N);
void dfs(int v, int p, int d){
    vis[v] = 1;
    for(int u: g[v]){
        for(int mask = 0; mask < (1<<k); ++mask){
            if(__builtin_popcount(mask) == d){
                if(!(mask&(1<<a[v]))) continue;
                if(a[u] != a[v]){
                    dp[v][mask] += dp[u][mask ^ (1<<a[v])];
                    ans += dp[u][mask ^ (1<<a[v])];
                }
            }
        }
        if(vis[u]) continue;
        dfs(u, v, d);
    }
}


void solve(){
    cin >> n >> m >> k;
    for(int i = 1; i <= n; ++i) cin >> a[i];
    for(int i = 1; i <= n; ++i){
        --a[i];
        for(int j = 0; j < (1<<k); ++j) dp[i][j] = 0;
        dp[i][1<<a[i]]++;
    }
    for(int i = 0; i < m; ++i){
        int u, v; cin >> u >> v;
        g[u].pb(v);
        g[v].pb(u);
    }
    for(int j = 2; j <= k; ++j){
        vis.clear();
        vis.resize(n+1);
        for(int i = 1; i <= n; ++i) if(!vis[i]) dfs(i, 0, j);
    }
    cout << ans;
}   





int main(){
    cin.tie(0); ios::sync_with_stdio(0);
    int T = 1, aa;
    // cin >> T;aa=T;
    while(T--){
        // cout << "Case #" << aa-T << ": ";
        solve();
        cout << '\n';
    }
    return 0;
 
}

Compilation message (stderr)

paths.cpp: In function 'int main()':
paths.cpp:66:16: warning: unused variable 'aa' [-Wunused-variable]
   66 |     int T = 1, aa;
      |                ^~

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