Submission #1051252

#	Time	Username	Problem	Language	Result	Execution time	Memory
1051252		Whisper	Drivers (BOI24_drivers)	C++17	100 / 100	213 ms	106324 KiB

Main

#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, a) for (int i = 0; i < (a); ++i)
#define REPD(i, a) for (int i = (a) - 1; i >= 0; --i)

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


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

/*
    Phu Trong from Nguyen Tat Thanh High School for gifted student
*/

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, numQuery;
#define MAX                 200005
#define LOG                     20

struct Edge{
    int u, v, w;
    Edge(){}
    Edge(int _u, int _v, int _w): u(_u), v(_v), w(_w){}

    int other(int x){
        return (x ^ u ^ v);
    }

    bool operator < (const Edge& oth) const{
        return w < oth.w;
    }
} edge[MAX];

vector<int> G[MAX];

int ID[MAX];

int pa[MAX];

int find(int u){
    return u == pa[u] ? u : pa[u] = find(pa[u]);
}
bool joint(int u, int v){
    u = find(u), v = find(v);
    if(u == v) return false;
    pa[v] = u;
    return true;
}
int cc = 1;
int up[MAX][LOG], mx[MAX][LOG];
int dep[MAX];
void pre_dfs(int u, int p = -1){
    ID[u] = cc;
    for (int&i : G[u]){
        int v = edge[i].other(u);
        if(v ^ p){
            up[v][0] = u;
            mx[v][0] = edge[i].w;
            dep[v] = dep[u] + 1;
            for (int i = 1; i < LOG; ++i){
                up[v][i] = up[up[v][i - 1]][i - 1];
                mx[v][i] = max(mx[v][i - 1], mx[up[v][i - 1]][i - 1]);
            }
            pre_dfs(v, u);
        }
    }
}

int lca(int u, int v){
    if (dep[u] < dep[v]) swap(u, v);
    int dis = dep[u] - dep[v];
    int ans = 0;
    for (int i = 0; MASK(i) <= dis; ++i){
        if (BIT(dis, i)){
            maximize(ans, mx[u][i]);
            u = up[u][i];
        }
    }
    if (u == v) return ans;
    for (int i = LOG - 1; i >= 0; --i) if(up[v][i] != up[u][i]){
        maximize(ans, mx[v][i]);
        maximize(ans, mx[u][i]);
        v = up[v][i], u = up[u][i];
    }
    maximize(ans, mx[v][0]);
    maximize(ans, mx[u][0]);
    return ans;
}
void process(void){
    cin >> numNode >> numEdge >> numQuery;
    for (int i = 1; i <= numEdge; ++i){
        cin >> edge[i].u >> edge[i].v >> edge[i].w;
    }
    for (int i = 1; i <= numNode; ++i) pa[i] = i;
    sort(edge + 1, edge + numEdge + 1);
    for (int i = 1; i <= numEdge; ++i){
        if (joint(edge[i].u, edge[i].v)){
            G[edge[i].u].emplace_back(i);
            G[edge[i].v].emplace_back(i);
        }
    }

    for (int i = 1; i <= numNode; ++i) if(!ID[i]){
        pre_dfs(i); ++cc;
    }
    for (int i = 1; i <= numQuery; ++i){
        int u, v, w; cin >> u >> v >> w;
        if (ID[u] != ID[v]){
            cout << "NE\n";
        }
        else{
            int val = lca(u, v);
            cout << (val <= w ? "TAIP\n" : "NE\n");
        }
    }
}
signed main(){
    #define name "Whisper"
    cin.tie(nullptr) -> sync_with_stdio(false);
    //freopen(name".inp", "r", stdin);
    //freopen(name".out", "w", stdout);
    process();
    return (0 ^ 0);
}

• Subtask 1: 10 / 10
• Subtask 2: 11 / 11
• Subtask 3: 11 / 11
• Subtask 4: 23 / 23
• Subtask 5: 45 / 45