Submission #988678

#	Time	Username	Problem	Language	Result	Execution time	Memory
988678		maomao90	Railway Trip 2 (JOI22_ho_t4)	C++17	100 / 100	269 ms	40028 KiB

Main

// Hallelujah, praise the one who set me free
// Hallelujah, death has lost its grip on me
// You have broken every chain, There's salvation in your name
// Jesus Christ, my living hope
#include <bits/stdc++.h> 
using namespace std;

#define REP(i, s, e) for (int i = (s); i < (e); i++)
#define RREP(i, s, e) for (int i = (s); i >= (e); i--)
template <class T>
inline bool mnto(T& a, T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T& a, T b) {return a < b ? a = b, 1: 0;}
typedef long long ll;
typedef long double ld;
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define SZ(_a) (int) _a.size()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
typedef vector<iii> viii;

#ifndef DEBUG
#define cerr if (0) cerr
#endif

const int INF = 1000000005;
const ll LINF = 1000000000000000005ll;
const int MAXN = 100005;
const int MAXM = 200005;
const int MAXL = 20;

int n, k, m;
ii ab[MAXM];
ii p[MAXL][MAXM];
ii src[MAXN];
int q;

ii fw[MAXN];
void upd(int i, ii x) {
    for (; i <= n; i += i & -i) {
        mxto(fw[i], x);
    }
}
ii qmx(int i) {
    ii res = {-INF, -INF};
    for (; i > 0; i -= i & -i) {
        mxto(res, fw[i]);
    }
    return res;
}

namespace DSU {
    int rt[MAXN], p[MAXN], rnk[MAXN];
    void init() {
        REP (i, 1, n + 2) {
            p[i] = i;
            rt[i] = i;
            rnk[i] = 1;
        }
    }
    int findp(int i) {
        if (p[i] == i) {
            return i;
        }
        return p[i] = findp(p[i]);
    }
    bool join(int a, int b) {
        int pa = findp(a), pb = findp(b);
        if (pa == pb) {
            return 0;
        }
        if (rnk[pa] < rnk[pb]) {
            swap(pa, pb);
        } else if (rnk[pa] == rnk[pb]) {
            rnk[pa]++;
        }
        p[pb] = pa;
        mxto(rt[pa], rt[pb]);
        return 1;
    }
}

int id[MAXM];
void precomp(bool b) {
    iota(id, id + m, 1);
    sort(id, id + m, [&] (int l, int r) {
            return ab[l].FI > ab[r].FI;
            });
    REP (i, 1, n + 1) {
        fw[i] = {-INF, 0};
    }
    REP (_, 0, m) {
        int i = id[_];
        if (ab[i].FI > ab[i].SE) {
            continue;
        }
        int r = qmx(ab[i].SE).SE;
        if (!r) {
            r = i;
        }
        (b ? p[0][i].FI : p[0][i].SE) = r;
        upd(ab[i].FI, {ab[i].SE, i});
    }
    sort(id, id + m, [&] (int l, int r) {
            auto get = [&] (int i) {
                return ab[i].FI < ab[i].SE ? ab[i].FI : ab[i].FI - k + 1;
            };
            return get(l) > get(r);
            });
    REP (i, 1, n + 1) {
        fw[i] = {-INF, 0};
    }
    REP (_, 0, m) {
        int i = id[_];
        if (ab[i].FI > ab[i].SE) {
            upd(max(ab[i].FI - k + 1, ab[i].SE), {-ab[i].SE, i});
        } else {
            int r = qmx(ab[i].SE).SE;
            if (!r) {
                r = i;
            }
            (b ? p[0][i].SE : p[0][i].FI) = r;
        }
    }

    sort(id, id + m, [&] (int l, int r) {
            return ab[l].SE > ab[r].SE;
            });
    DSU::init();
    REP (_, 0, m) {
        int i = id[_];
        if (ab[i].FI > ab[i].SE) {
            continue;
        }
        while (DSU::rt[DSU::findp(ab[i].FI)] <= min(ab[i].SE, ab[i].FI + k - 1)) {
            int x = DSU::rt[DSU::findp(ab[i].FI)];
            (b ? src[n - x + 1].FI : src[x].SE) = i;
            DSU::join(x, x + 1);
        }
    }
}

inline ii jump(ii x, int k) {
    ii res = x;
    auto relax = [&] (ii y) {
        if (!res.FI || ab[res.FI].SE > ab[y.FI].SE) {
            res.FI = y.FI;
        }
        if (!res.SE || ab[res.SE].SE < ab[y.SE].SE) {
            res.SE = y.SE;
        }
    };
    if (x.FI) {
        relax(p[k][x.FI]);
    }
    if (x.SE) {
        relax(p[k][x.SE]);
    }
    return res;
}

int main() {
#ifndef DEBUG
    ios::sync_with_stdio(0), cin.tie(0);
#endif
    cin >> n >> k;
    cin >> m;
    REP (i, 1, m + 1) {
        cin >> ab[i].FI >> ab[i].SE;
    }
    REP (b, 0, 2) {
        precomp(b);
        REP (i, 1, m + 1) {
            ab[i].FI = n - ab[i].FI + 1;
            ab[i].SE = n - ab[i].SE + 1;
        }
    }
    REP (k, 1, MAXL) {
        REP (i, 1, m + 1) {
            p[k][i] = jump(p[k - 1][i], k - 1);
        }
    }
    REP (i, 1, m + 1) {
        cerr << i << ": " << p[0][i].FI << ' ' << p[0][i].SE << '\n';
    }
    REP (i, 1, n + 1) {
        cerr << i << ": " << src[i].FI << ' ' << src[i].SE << '\n';
    }
    cin >> q;
    REP (i, 0, q) {
        int s, t; cin >> s >> t;
        ii u = src[s];
        if (s < t) {
            if (u.SE && ab[u.SE].SE >= t) {
                cout << 1 << '\n';
                continue;
            }
        } else {
            if (u.FI && ab[u.FI].SE <= t) {
                cout << 1 << '\n';
                continue;
            }
        }
        int res = 2;
        RREP (k, MAXL - 1, 0) {
            ii v = jump(u, k);
            if (!v.FI && !v.SE) {
                continue;
            }
            if (s < t) {
                if (!v.SE || ab[v.SE].SE < t) {
                    u = v;
                    res += 1 << k;
                }
            } else {
                if (!v.FI || ab[v.FI].SE > t) {
                    u = v;
                    res += 1 << k;
                }
            }
        }
        u = jump(u, 0);
        if (s < t) {
            if (!u.SE || ab[u.SE].SE < t) {
                res = -1;
            }
        } else {
            if (!u.FI || ab[u.FI].SE > t) {
                res = -1;
            }
        }
        cout << res << '\n';
    }
    return 0;
}

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