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Submission #673963

# Submission time Handle Problem Language Result Execution time Memory
673963 2022-12-22T13:19:27 Z stanislavpolyn Event Hopping (BOI22_events) C++17
60 / 100
 1500 ms 16600 KB 
#include <bits/stdc++.h>

#define fr(i, a, b) for (int i = (a); i <= (b); ++i)
#define rf(i, a, b) for (int i = (a); i >= (b); --i)
#define fe(x, y) for (auto& x : y)

#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define mt make_tuple

#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
#define pw(x) (1LL << (x))

using namespace std;

mt19937_64 rng(228);

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <typename T>
using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define fbo find_by_order
#define ook order_of_key

template <typename T>
bool umn(T& a, T b) {
    return a > b ? a = b, 1 : 0;
}
template <typename T>
bool umx(T& a, T b) {
    return a < b ? a = b, 1 : 0;
}

using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
template <typename T>
using ve = vector<T>;

const int N = 1e5 + 5;

int n, q;
pii a[N];

ve<int> order;

int to[N];
int d[N];
ve<pii> Q[N];
int ans[N];
//bool subtask1 = 1;

pii get(int v) {
    if (to[v] == v) {
        return {v, 0};
    } else {
        pii p = get(to[v]);
        p.se += d[v];
        to[v] = p.fi;
        d[v] = p.se;
        return {p.fi, p.se};
    }
}

bool TL() {
    return (double)clock() / CLOCKS_PER_SEC > 1.4;
}

ve<int> st;

bool have[N];
bool subtask = 1;

int go[N][20];

int main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#else
    ios::sync_with_stdio(0);
    cin.tie(0);
#endif

    cin >> n >> q;

//    subtask1 &= n > 5000 || q > 100;

    ve<int> u;
    fr (i, 1, n) {
        cin >> a[i].fi >> a[i].se;
        order.pb(i);
        u.pb(a[i].se);
    }

    sort(all(u));

    {
        sort(all(order), [](int i, int j) {
            return a[i].fi < a[j].fi || (a[i].fi == a[j].fi && a[i].se > a[j].se);
        });

        fe (i, order) {
            if (sz(st) && a[st.back()].se >= a[i].se) {
                to[i] = st.back();
                continue;
            }
            st.pb(i);
            have[i] = 1;
        }


        fr (i, 1, sz(st) - 1) {
            assert(a[st[i]].fi > a[st[i - 1]].fi);
            assert(a[st[i]].se > a[st[i - 1]].se);
        }

        {
            int mx = -1e9;
            int mxI = -1;
            int ptr = 0;

            fe (i, st) {
                while (ptr < sz(st) && a[st[ptr]].fi <= a[i].se) {
                    if (umx(mx, a[st[ptr]].se)) {
                        mxI = st[ptr];
                    }
                    ptr++;
                }

                if (mx >= a[i].se) {
                    to[i] = mxI;
                } else {
                    assert(0);
                    to[i] = -1;
                }
            }
        }

        subtask &= sz(st) == n;
    }

    if (subtask) {
        fr (i, 1, n) {
            go[i][0] = to[i];
        }
        fr (p, 1, 19) {
            fr (i, 1, n) {
                go[i][p] = go[go[i][p - 1]][p - 1];
            }
        }

        fr (i, 1, q) {
            int s, e;
            cin >> s >> e;

            if (s == e) {
                cout << "0\n";
                continue;
            }

            if (a[s].se > a[e].se) {
                cout << "impossible\n";
                continue;
            }

            int v = s;
            int ans = 0;

            rf (p, 19, 0) {
                if (!go[v][p]) continue;

                int nxt = go[v][p];
                if (a[nxt].se < a[e].se) {
                    v = go[v][p];
                    ans += pw(p);
                }
            }

            while (1) {
                if (a[to[v]].se == a[v].se || a[to[v]].se > a[e].se || a[v].se >= a[e].fi) {
                    break;
                }
                v = to[v];
                ans++;
            }

            if (a[v].se >= a[e].fi) {
                ans++;
                cout << ans << "\n";
            } else {
                cout << "impossible\n";
            }

        }


        return 0;
    }

//    fr (i, 1, n) {
//        int p1 = lower_bound(all(u), a[i].fi) - u.begin();
//        int p2 = upper_bound(all(u), a[i].se) - u.begin() - 1;
//        if (max(0, p2 - p1 + 1) > 2) {
//            assert(0);
//        }
//    }

//    fr (i, 1, n) {
//        int cnt = 0;
//        fr (j, 1, n) {
//            if (i == j) continue;
//
//            if (a[j].fi <= a[i].se && a[i].se <= a[j].se) {
//                cnt++;
//            }
//        }
//        assert(cnt <= 1);
//    }

    fr (i, 1, q) {
        int s, e;
        cin >> s >> e;

        if (s == e) {
            ans[i] = 0;
            continue;
        }

        if (a[s].se >= a[e].fi && a[s].se <= a[e].se) {
            ans[i] = 1;
            continue;
        }

        if (a[s].se > a[e].se) {
            ans[i] = -1;
            continue;
        }
        Q[e].pb({s, i});
    }


    sort(all(order), [](int i, int j) {
        return a[i].se < a[j].se || (a[i].se == a[j].se && a[i].fi < a[j].fi);
    });

    fr (i, 1, n) {
        to[i] = i;
        d[i] = 0;
    }

//    subtask1 = 1;

    ve<pii> add, del;
    fr (idx, 0, sz(order) - 1) {
        int i = order[idx];

        int l = 0;
        int r = idx - 1;
        while (l < r) {
            int mid = l + ((r - l) >> 1);
            int j = order[mid];

            if (a[j].se < a[i].fi) {
                l = mid + 1;
            } else {
                r = mid;
            }
        }

        if (a[order[l]].se < a[i].fi) {
            l++;
        }

        if (l <= idx - 1) {

//            rf (ptr, idx - 1, l) {
//                int j = order[ptr];
//                to[j] = i;
//                d[j] = 1;
//            }

            add.pb({l, idx});
            del.pb({idx, idx});
        }

//        rf (ptr, idx - 1, 0) {
//            int j = order[ptr];
//            if (a[j].se < a[i].fi) {
//                break;
//            }
//
//            subtask1 &= ptr == idx - 1;
//            to[j] = i;
//            d[j] = 1;
//        }

        if (sz(Q[i])) {
            sort(all(add));
            sort(all(del));
//
            int ptr1 = 0;
            int ptr2 = 0;
            set<int> s;
            fr (cur, 0, idx) {
                while (ptr1 < sz(add) && add[ptr1].fi <= cur) {
                    s.insert(add[ptr1].se);
                    ptr1++;
                }
                while (ptr2 < sz(del) && del[ptr2].fi <= cur) {
                    s.erase(del[ptr2].se);
                    ptr2++;
                }

                int i = order[cur];

                if (sz(s)) {
                    d[i] = 1;
//                    assert(to[i] == order[*s.rbegin()]);
                    to[i] = order[*s.rbegin()];
                }
            }

            add.clear();
            del.clear();
        }

        fe (cur, Q[i]) {
            int v = cur.fi;
            int sum = 0;
            while (to[v] != v) {
                sum += d[v];
                v = to[v];
            }
//            cout << "YEP " << i << "\n";
//            cout << "start " << cur.fi << "\n";

//            cout << "to: " << to[cur.fi] << "\n";

            if (v == i) {
                ans[cur.se] = sum;
            } else {
                ans[cur.se] = -1;
            }
        }
    }

    fr (i, 1, q) {
        if (ans[i] == -1) {
            cout << "impossible\n";
        } else {
            cout << ans[i] << "\n";
        }
    }

    return 0;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 92 ms 13964 KB Output is correct
3 Correct 92 ms 13728 KB Output is correct
4 Correct 126 ms 13748 KB Output is correct
5 Execution timed out 1569 ms 9200 KB Time limit exceeded
6 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2692 KB Output is correct
2 Correct 2 ms 2696 KB Output is correct
3 Correct 2 ms 2772 KB Output is correct
4 Correct 2 ms 2772 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2644 KB Output is correct
7 Correct 2 ms 2772 KB Output is correct
8 Correct 2 ms 2772 KB Output is correct
9 Correct 2 ms 2772 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2692 KB Output is correct
2 Correct 2 ms 2696 KB Output is correct
3 Correct 2 ms 2772 KB Output is correct
4 Correct 2 ms 2772 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2644 KB Output is correct
7 Correct 2 ms 2772 KB Output is correct
8 Correct 2 ms 2772 KB Output is correct
9 Correct 2 ms 2772 KB Output is correct
10 Correct 2 ms 2644 KB Output is correct
11 Correct 2 ms 2700 KB Output is correct
12 Correct 2 ms 2832 KB Output is correct
13 Correct 3 ms 2772 KB Output is correct
14 Correct 2 ms 2676 KB Output is correct
15 Correct 2 ms 2708 KB Output is correct
16 Correct 3 ms 2712 KB Output is correct
17 Correct 2 ms 2820 KB Output is correct
18 Correct 3 ms 2712 KB Output is correct
19 Correct 477 ms 5208 KB Output is correct
20 Correct 28 ms 3788 KB Output is correct
21 Correct 296 ms 4792 KB Output is correct
22 Correct 67 ms 4556 KB Output is correct
23 Correct 79 ms 4216 KB Output is correct
24 Correct 25 ms 3932 KB Output is correct
25 Correct 36 ms 3612 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 2692 KB Output is correct
2 Correct 2 ms 2696 KB Output is correct
3 Correct 2 ms 2772 KB Output is correct
4 Correct 2 ms 2772 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2644 KB Output is correct
7 Correct 2 ms 2772 KB Output is correct
8 Correct 2 ms 2772 KB Output is correct
9 Correct 2 ms 2772 KB Output is correct
10 Correct 2 ms 2704 KB Output is correct
11 Correct 2 ms 2700 KB Output is correct
12 Correct 2 ms 2772 KB Output is correct
13 Correct 2 ms 2836 KB Output is correct
14 Correct 3 ms 2644 KB Output is correct
15 Correct 2 ms 2644 KB Output is correct
16 Correct 2 ms 2772 KB Output is correct
17 Correct 2 ms 2772 KB Output is correct
18 Correct 2 ms 2712 KB Output is correct
19 Correct 51 ms 13200 KB Output is correct
20 Correct 82 ms 5440 KB Output is correct
21 Correct 98 ms 5400 KB Output is correct
22 Correct 76 ms 5816 KB Output is correct
23 Correct 48 ms 13184 KB Output is correct
24 Correct 48 ms 13172 KB Output is correct
25 Correct 28 ms 7544 KB Output is correct

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 71 ms 13904 KB Output is correct
2 Correct 91 ms 13832 KB Output is correct
3 Correct 115 ms 13720 KB Output is correct
4 Correct 71 ms 14276 KB Output is correct
5 Correct 87 ms 14076 KB Output is correct
6 Correct 99 ms 13864 KB Output is correct
7 Correct 92 ms 14012 KB Output is correct
8 Correct 79 ms 14072 KB Output is correct
9 Correct 49 ms 13180 KB Output is correct
10 Correct 106 ms 16488 KB Output is correct
11 Correct 71 ms 16352 KB Output is correct
12 Correct 85 ms 16600 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 92 ms 13964 KB Output is correct
3 Correct 92 ms 13728 KB Output is correct
4 Correct 126 ms 13748 KB Output is correct
5 Execution timed out 1569 ms 9200 KB Time limit exceeded
6 Halted 0 ms 0 KB -