Submission #597073

#	Time	Username	Problem	Language	Result	Execution time	Memory
597073		dxz05	Railway Trip 2 (JOI22_ho_t4)	C++14	52 / 100	2057 ms	45388 KiB

Main

//#pragma GCC optimize("Ofast,O2,O3,unroll-loops")
//#pragma GCC target("avx2")

#include <bits/stdc++.h>

using namespace std;

void debug_out() { cerr << endl; }

template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << "[" << H << "]";
    debug_out(T...);
}

#ifdef dddxxz
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

#define SZ(s) ((int)s.size())
#define all(x) (x).begin(), (x).end()
#define lla(x) (x).rbegin(), (x).rend()
#define bpc(x) __builtin_popcount(x)
#define bpcll(x) __builtin_popcountll(x)
#define MP make_pair

clock_t startTime;

double getCurrentTime() {
    return (double) (clock() - startTime) / CLOCKS_PER_SEC;
}

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

typedef long long ll;
const int MOD = 1e9 + 7;
const int INF = 1000000101;
const long long LLINF = 1223372000000000555;
const int N = 1e5 + 3e2;
const int M = 5555;

int n;
vector<int> lf, rg;
vector<pair<int, int>> queries;

void Subtask_4(){
    vector<vector<int>> pl(n, vector<int>(20, 0));
    for (int i = 0; i < n; i++){
        pl[i][0] = lf[i];
        for (int j = 1; j < 20; j++){
            pl[i][j] = pl[pl[i][j - 1]][j - 1];
        }
    }

    vector<vector<int>> pr(n, vector<int>(20, 0));
    for (int i = n - 1; i >= 0; i--){
        pr[i][0] = rg[i];
        for (int j = 1; j < 20; j++){
            pr[i][j] = pr[pr[i][j - 1]][j - 1];
        }
    }

    function<int(int, int)> get_dist = [&](int x, int y){
        if (x == y) return 0;

        int ret = 0;
        if (x < y) {
            if (pr[x].back() < y) return -1;
            for (int i = (int)pr[x].size() - 1; i >= 0; i--) {
                if (pr[x][i] >= y) continue;
                x = pr[x][i];
                ret += 1 << i;
            }
        } else {
            if (pl[x].back() > y) return -1;
            for (int i = (int)pl[x].size() - 1; i >= 0; i--) {
                if (pl[x][i] <= y) continue;
                x = pl[x][i];
                ret += 1 << i;
            }
        }

        return ret + 1;
    };

    for (auto qu : queries){
        cout << get_dist(qu.first, qu.second) << endl;
    }

    exit(0);
}

struct SegTree{
    int size;
    vector<int> tree;

    void init(int sz){
        size = sz;
        tree.assign(4 * sz + 2, INF);
    }

    void update(int v, int tl, int tr, int pos, int val){
        if (tl == tr){
            tree[v] = min(tree[v], val);
            return;
        }
        int tm = (tl + tr) >> 1;
        if (pos <= tm){
            update(v << 1, tl, tm, pos, val);
        } else {
            update(v << 1 | 1, tm + 1, tr, pos, val);
        }
        tree[v] = min(tree[v << 1], tree[v << 1 | 1]);
    }

    void update(int pos, int val){
        update(1, 0, size - 1, pos, val);
    }

    int get(int v, int tl, int tr, int l, int r){
        if (l <= tl && tr <= r) return tree[v];
        if (tl > r || tr < l) return INF;
        int tm = (tl + tr) >> 1;
        return min(get(v << 1, tl, tm, l, r), get(v << 1 | 1, tm + 1, tr, l, r));
    }

    int get(int l, int r){
        return get(1, 0, size - 1, l, r);
    }
};

int get_dist(int foo, int hoo){
    queue<int> q;
    set<int> s;
    vector<int> d(n, -1);
    for (int i = 0; i < n; i++) s.insert(i);

    q.push(foo);
    s.erase(foo);
    d[foo] = 0;

    while (!q.empty()){
        int x = q.front();
        q.pop();

        while (!s.empty()){
            auto it = s.lower_bound(lf[x]);
            if (it != s.end() && *it <= rg[x]){
                int y = *it;
                q.push(y);
                s.erase(y);
                d[y] = d[x] + 1;
            } else {
                break;
            }
        }

    }

    return d[hoo];
}

void solve(int TC) {
    int k, trips;
    cin >> n >> k >> trips;

    vector<vector<int>> open_l(n), close_l(n);
    vector<vector<int>> open_r(n), close_r(n);
    while (trips--){
        int a, b;
        cin >> a >> b;
        --a, --b;

        if (a < b){
            open_r[a].push_back(b);
            close_r[min(a + k, b) - 1].push_back(b);
        } else {
            open_l[a].push_back(b);
            close_l[max(a - k, b) + 1].push_back(b);
        }

    }

    lf.assign(n, 0);
    rg.assign(n, 0);
    iota(all(lf), 0);
    iota(all(rg), 0);

    multiset<int> ms;
    for (int i = 0; i < n; i++){
        for (int r : open_r[i]) ms.insert(r);
        if (!ms.empty()) rg[i] = *ms.rbegin();
        for (int r : close_r[i]) ms.erase(ms.find(r));
    }

    ms.clear();
    for (int i = n - 1; i >= 0; i--){
        for (int l : open_l[i]) ms.insert(l);
        if (!ms.empty()) lf[i] = *ms.begin();
        for (int l : close_l[i]) ms.erase(ms.find(l));
    }

    int q;
    cin >> q;

    while (q--){
        int s, t;
        cin >> s >> t;
        --s, --t;
        queries.emplace_back(s, t);
    }

    if (k == n - 1) Subtask_4();


    for (auto qu : queries){
        int s = qu.first, t = qu.second;
        cout << get_dist(s, t) << endl;
    }

}

int main() {
    startTime = clock();
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);

#ifdef dddxxz
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    int TC = 1;
//    cin >> TC;

    for (int test = 1; test <= TC; test++) {
        //debug(test);
        //cout << "Case #" << test << ": ";
        solve(test);
    }

#ifdef dddxxz
    cerr << endl << "Time: " << int(getCurrentTime() * 1000) << " ms" << endl;
#endif

    return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 11 / 11
• Subtask 4: 25 / 25
• Subtask 5: 0 / 35
• Subtask 6: 0 / 13