Submission #1038150

#	Time	Username	Problem	Language	Result	Execution time	Memory
1038150		Whisper	Rigged Roads (NOI19_riggedroads)	C++17	100 / 100	353 ms	92940 KiB

riggedroads

#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;
#define MAX             300005
#define LOG             20

bool in[MAX];
struct Edge{
    int u, v;
    Edge(){}
    Edge(int _u, int _v):u(_u), v(_v){}

    int other(int x){
        return (x ^ u ^ v);
    }
} edge[MAX];

vector<int> G[MAX];

int up[MAX][21], to[MAX], dep[MAX];
void dfs(int u, int p = -1){
    for (int&i : G[u]){
        int v = edge[i].other(u);
        if(v ^ p){
            up[v][0] = u;
            dep[v] = dep[u] + 1;
            to[v] = i;
            for (int i = 1; i < LOG; ++i) up[v][i] = up[up[v][i - 1]][i - 1];
            dfs(v, u);
        }
    }
}

int lca(int u, int v){
    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)){
        u = up[u][i];
    }
    if(u == v) return u;
    int k = __lg(dep[u]);
    for (int i = k; i >= 0; --i) if(up[u][i] != up[v][i]){
        u = up[u][i], v = up[v][i];
    }
    return up[u][0];
}


bool assigned[MAX];

int ans[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;
}

void process(void){
    cin >> numNode >> numEdge;

    for (int i = 1; i <= numEdge; ++i){
        cin >> edge[i].u >> edge[i].v;
    }

    for (int i = 1; i < numNode; ++i){
        int id; cin >> id;
        G[edge[id].u].emplace_back(id);
        G[edge[id].v].emplace_back(id);
        in[id] = true;
    }

    dfs(1);
    int label = 0;
    for (int i = 1; i <= numNode; ++i) pa[i] = i;
    for (int i = 1; i <= numEdge; ++i){
        if(assigned[i]) continue;
        assigned[i] = true;
        if(in[i]){
            ans[i] = ++label;
            if (dep[edge[i].u] < dep[edge[i].v]) swap(edge[i].u, edge[i].v);
            joint(edge[i].v, edge[i].u);
            continue;
        }

        vector<int> target;

        int anc = lca(edge[i].u, edge[i].v);
        for (int node : {edge[i].u, edge[i].v}){
            while(node != anc && dep[find(node)] >= dep[anc]){
                node = find(node);
                if(node == anc) break;

                if (to[node]) target.push_back(to[node]);
                joint(up[node][0], node);
                node = up[node][0];
            }
        }
        sort(target.begin(), target.end());

        for (int &id : target){
            if(assigned[id]) continue;
            ans[id] = ++label;
            assigned[id] = true;
        }
        ans[i] = ++label;
    }
    for (int i = 1; i <= numEdge; ++i){
        cout << ans[i] << " ";
    }
}
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: 8 / 8
• Subtask 2: 19 / 19
• Subtask 3: 9 / 9
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 12 / 12
• Subtask 7: 32 / 32