Submission #940240

#	Time	Username	Problem	Language	Result	Execution time	Memory
940240		Whisper	Paths (BOI18_paths)	C++17	0 / 100	743 ms	1048576 KiB

paths

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

#define int long long
#define FOR(i, a, b) for ( int i = a ; i <= b ; i++ )
#define FORD(i, a, b) for (int i = b; i >= a; i --)
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPD(i, n) for (int i = n - 1; i >= 0; --i)
#define Lg(x) 31 - __builtin_clz(x)

#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)

constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int MAX = 3e5 + 5;
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void setupIO(){
    #define name "Whisper"
    //Phu Trong from Nguyen Tat Thanh High School for gifted student
    srand(time(NULL));
    cin.tie(nullptr)->sync_with_stdio(false); cout.tie(nullptr);
    //freopen(name".inp", "r", stdin);
    //freopen(name".out", "w", stdout);
    cout << fixed << setprecision(10);
}

template <class X, class Y>
    bool minimize(X &x, const Y &y){
        X eps = 1e-9;
        if (x > y + eps) {x = y; return 1;}
        return 0;
    }

template <class X, class Y>
    bool maximize(X &x, const Y &y){
        X eps = 1e-9;
        if (x + eps < y) {x = y; return 1;}
        return 0;
    }
int numNode, numEdge, numColor;
vector<int> G[MAX];
int C[MAX];

int down[MAX][MASK(5)], up[MAX][MASK(5)];

int ans = 0;
void dfs_up(int u, int p = -1){
    up[u][MASK(C[u])] = 1;
    for (int &v : G[u]) if(v ^ p){
        dfs_up(v, u);
        for (int msk = 0; msk < MASK(numColor); ++msk){
            if (!BIT(msk, C[u])) up[u][msk | MASK(C[u])] += up[v][msk];
        }
    }
}


void dfs_down(int u, int p = -1){
    down[u][MASK(C[u])] = 1;
    for (int &v : G[u]) if(v ^ p){
        for (int msk = 0; msk < MASK(numColor); ++msk){
            if (!BIT(msk, C[v])){
                down[v][MASK(C[v]) | msk] += down[u][msk];
                down[v][MASK(C[v]) | msk] += up[u][msk];
            }
        }
        dfs_down(v, u);
    }
}
void Whisper(){
    cin >> numNode >> numEdge >> numColor;
    for (int i = 1; i <= numNode; ++i){
        cin >> C[i];
        --C[i];
    }
    for (int i = 1; i <= numEdge; ++i){
        int u, v; cin >> u >> v;
        G[u].push_back(v);
        G[v].push_back(u);
    }
    dfs_up(1);
    dfs_down(1);
    int ans = 0;
    for (int msk = 0; msk < MASK(numColor); ++msk){
        if (__builtin_popcount(msk) <= 1) continue;
        for (int u = 1; u <= numNode; ++u){
            ans += down[u][msk];
        }
    }
    cout << ans;
}


signed main(){
    setupIO();
    int Test = 1;
//    cin >> Test;
    for ( int i = 1 ; i <= Test ; i++ ){
        Whisper();
        if (i < Test) cout << '\n';
    }
}

• Subtask 1: 0 / 23
• Subtask 2: 0 / 20
• Subtask 3: 0 / 27
• Subtask 4: 0 / 30