Submission #918301

#	Time	Username	Problem	Language	Result	Execution time	Memory
918301		Whisper	Evacuation plan (IZhO18_plan)	C++17	100 / 100	651 ms	188164 KiB

plan

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using ld = long double;
using T = tuple<ll, ll, ll>;

#define int long long
#define Base 41
#define sz(a) (int)a.size()
#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 all(x) x.begin() , x.end()
#define pii pair<int , int>
#define fi first
#define se second
#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 = 5e5 + 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 N, M, K, Q;
vector<pii> adj[MAX];
int g[MAX];
int f[MAX];

struct Dsu{
    int n;
    vector<int> par, sz;
    Dsu(int _n){
        this -> n = _n;
        par.resize(n + 5);
        sz.resize(n + 5, 1);
        iota(par.begin(), par.end(), 0ll);
    }
    int Find(int u){
        return u == par[u] ? u : par[u] = Find(par[u]);
    }
    bool unite(int u, int v){
        u = Find(u), v = Find(v);
        if (u == v) return 0;
        if (sz[u] < sz[v]) swap(u, v);
        sz[u] += sz[v];
        par[v] = u;
        return 1;
    }
};

struct Data{
    int u, v, w;
    bool operator < (const Data& oth) const{
        return w > oth.w;
    }
};


int up[MAX][21], dep[MAX], mn[MAX][21];
void dfs(int u, int p){
    for (auto&[v, w] : adj[u]) if(v ^ p){
        up[v][0] = u;
        mn[v][0] = w;
        dep[v] = dep[u] + 1;
        for (int i = 1; i <= 20; ++i){
            up[v][i] = up[up[v][i - 1]][i - 1];
            mn[v][i] = min(mn[v][i - 1], mn[up[v][i - 1]][i - 1]);
        }
        dfs(v, u);
    }
}

int query(int u, int v){
    int ans = INF;
    if (dep[u] < dep[v]) swap(u, v);
    int dis = dep[u] - dep[v];
    for (int i = 0; MASK(i) <= dis; ++i){
        if (BIT(dis, i)) minimize(ans, mn[u][i]), u = up[u][i];
    }
    if (u == v) return ans;
    int k = Lg(dep[v]);
    for (int i = k; i >= 0; --i) if(up[u][i] != up[v][i]){
        minimize(ans, mn[u][i]);
        minimize(ans, mn[v][i]);
        u = up[u][i], v = up[v][i];
    }
    minimize(ans, mn[u][0]); minimize(ans, mn[v][0]);
    return ans;
}
void Whisper(){
    cin >> N >> M;
    for (int i = 1; i <= M; ++i){
        int u, v, w; cin >> u >> v >> w;
        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
    }
    cin >> K;
    priority_queue<pii, vector<pii>, greater<pii>> q;
    memset(f, 0x3f, sizeof f);
    for (int i = 1; i <= K; ++i){
        cin >> g[i];
        q.push({0, g[i]});
        f[g[i]] = 0;
    }
    vector<int> vis(N + 1);
    while (!q.empty()){
        auto[du, u] = q.top(); q.pop();
        if (vis[u]) continue; vis[u] = 1;
        for (auto&[v, w] : adj[u]){
            if (minimize(f[v], f[u] + w)){
                q.push({f[v], v});
            }
        }
    }

    vector<int> ord(N + 1);
    iota(ord.begin(), ord.end(), 0);
    vector<Data> ed;
    for (int i = 1; i <= N; ++i){
        int u = ord[i];
        for (auto&[v, w] : adj[u]){
            int weight = min(f[u], f[v]);
            ed.push_back({u, v, weight});
        }
    }
    sort(all(ed));
    FOR(i, 0, N) adj[i].clear();
    Dsu dsu(N);
    for (auto&[u, v, w] : ed){
        if (dsu.unite(u, v)){
            adj[u].push_back({v, w});
            adj[v].push_back({u, w});
        }
    }
    memset(mn, 0x3f, sizeof mn);
    dfs(1, 0);
    cin >> Q;
    for (int i = 1; i <= Q; ++i){
        int u, v; cin >> u >> v;
        cout << query(u, v) << '\n';
    }

}


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

Compilation message (stderr)

plan.cpp: In function 'void Whisper()':
plan.cpp:137:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  137 |         if (vis[u]) continue; vis[u] = 1;
      |         ^~
plan.cpp:137:31: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  137 |         if (vis[u]) continue; vis[u] = 1;
      |                               ^~~

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 19 / 19
• Subtask 5: 46 / 46