Submission #738168

#	Time	Username	Problem	Language	Result	Execution time	Memory
738168		maomao90	Railway Trip 2 (JOI22_ho_t4)	C++17	25 / 100	117 ms	13684 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 MAXQ = 50005;
const int MAXL = 17;

int n, k, m;
ii ab[MAXM];
int q;
int p[MAXL][MAXN];
int mx[MAXN];
ii st[MAXQ];
int ans[MAXQ];

int par[MAXN], rnk[MAXN], rt[MAXN];
void init() {
    REP (i, 1, n + 2) {
        par[i] = i;
        rnk[i] = 1;
        rt[i] = i;
    }
}
int findp(int i) {
    if (par[i] == i) {
        return i;
    }
    return par[i] = findp(par[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);
    }
    if (rnk[pa] == rnk[pb]) {
        rnk[pa]++;
    }
    par[pb] = pa;
    mxto(rt[pa], rt[pb]);
    return 1;
}

void solve() {
    sort(ab, ab + m, [&] (ii l, ii r) {
            return l.FI < r.FI;
            });
    REP (i, 1, n + 1) {
        p[0][i] = -1;
    }
    int prv = 0;
    REP (i, 0, m) {
        auto [a, b] = ab[i];
        if (a > b) {
            continue;
        }
        REP (j, max(prv, a), b + 1) {
            cerr << j << ": " << a << '\n';
            p[0][j] = a;
        }
        mxto(prv, b + 1);
    }
    REP (k, 1, MAXL) {
        REP (i, 1, n + 1) {
            if (p[k - 1][i] == -1) {
                p[k][i] = -1;
            } else {
                p[k][i] = p[k - 1][p[k - 1][i]];
            }
        }
    }
    sort(ab, ab + m, [&] (ii l, ii r) {
            return l.SE > r.SE;
            });
    init();
    REP (i, 1, n + 1) {
        mx[i] = i;
    }
    REP (i, 0, m) {
        auto [a, b] = ab[i];
        if (a > b) {
            continue;
        }
        while (rt[findp(a)] < min(a + k, b)) {
            assert(mxto(mx[rt[findp(a)]], b));
            join(rt[findp(a)], rt[findp(a)] + 1);
        }
    }
    REP (i, 0, q) {
        auto [s, t] = st[i];
        if (s > t) {
            continue;
        }
        int res = 0;
        RREP (k, MAXL - 1, 0) {
            if (p[k][t] != -1 && p[k][t] > s) {
                t = p[k][t];
                res += 1 << k;
            }
        }
        if (mx[s] >= t) {
            ans[i] = res + 1;
        } else {
            ans[i] = -1;
        }
    }
}

int main() {
#ifndef DEBUG
    ios::sync_with_stdio(0), cin.tie(0);
#endif
    cin >> n >> k >> m;
    REP (i, 0, m) {
        cin >> ab[i].FI >> ab[i].SE;
    }
    cin >> q;
    REP (i, 0, q) {
        cin >> st[i].FI >> st[i].SE;
    }
    solve();
    REP (i, 0, m) {
        ab[i].FI = n - ab[i].FI + 1;
        ab[i].SE = n - ab[i].SE + 1;
    }
    REP (i, 0, q) {
        st[i].FI = n - st[i].FI + 1;
        st[i].SE = n - st[i].SE + 1;
    }
    solve();
    REP (i, 0, q) {
        cout << ans[i] << '\n';
    }
    return 0;
}

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