oj.uz

Submission #673969

# Submission time Handle Problem Language Result Execution time Memory
673969 2022-12-22T13:24:56 Z stanislavpolyn Event Hopping (BOI22_events) C++17
40 / 100
 1500 ms 14140 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;
bool subtask1;

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;

    if (q > 100 || n > 5000) {
        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) {

            if (subtask1) {
                rf (ptr, idx - 1, l) {
                    int j = order[ptr];
                    to[j] = i;
                    d[j] = 1;
                }
            } else {
                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 (!subtask1 && 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]) {
            if (subtask1) {
                auto p = get(cur.fi);

                if (p.fi == i) {
                    ans[cur.se] = p.se;
                } else {
                    ans[cur.se] = -1;
                }
            } else {
                int v = cur.fi;
                int sum = 0;
                while (to[v] != v) {
                    sum += d[v];
                    v = to[v];
                }

                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
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 88 ms 13604 KB Output is correct
3 Correct 89 ms 13596 KB Output is correct
4 Correct 126 ms 13708 KB Output is correct
5 Correct 75 ms 10440 KB Output is correct
6 Correct 72 ms 10016 KB Output is correct
7 Correct 74 ms 10048 KB Output is correct
8 Correct 61 ms 7612 KB Output is correct
9 Correct 71 ms 14116 KB Output is correct
10 Correct 90 ms 14016 KB Output is correct
11 Correct 82 ms 7840 KB Output is correct
12 Correct 49 ms 8208 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 1 ms 2644 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 2644 KB Output is correct
8 Correct 2 ms 2772 KB Output is correct
9 Correct 2 ms 2652 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 1 ms 2644 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 2644 KB Output is correct
8 Correct 2 ms 2772 KB Output is correct
9 Correct 2 ms 2652 KB Output is correct
10 Correct 1 ms 2644 KB Output is correct
11 Correct 2 ms 2644 KB Output is correct
12 Correct 2 ms 2772 KB Output is correct
13 Correct 2 ms 2772 KB Output is correct
14 Correct 2 ms 2644 KB Output is correct
15 Correct 2 ms 2644 KB Output is correct
16 Correct 3 ms 2644 KB Output is correct
17 Correct 2 ms 2772 KB Output is correct
18 Correct 2 ms 2644 KB Output is correct
19 Incorrect 43 ms 4860 KB Output isn't correct
20 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 1 ms 2644 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 2644 KB Output is correct
8 Correct 2 ms 2772 KB Output is correct
9 Correct 2 ms 2652 KB Output is correct
10 Correct 1 ms 2644 KB Output is correct
11 Correct 1 ms 2644 KB Output is correct
12 Correct 2 ms 2772 KB Output is correct
13 Correct 2 ms 2772 KB Output is correct
14 Correct 2 ms 2644 KB Output is correct
15 Correct 2 ms 2644 KB Output is correct
16 Correct 3 ms 2644 KB Output is correct
17 Correct 2 ms 2772 KB Output is correct
18 Correct 2 ms 2644 KB Output is correct
19 Correct 56 ms 13040 KB Output is correct
20 Correct 50 ms 5440 KB Output is correct
21 Execution timed out 1577 ms 5248 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 86 ms 13632 KB Output is correct
2 Correct 93 ms 13596 KB Output is correct
3 Correct 104 ms 13608 KB Output is correct
4 Correct 72 ms 14140 KB Output is correct
5 Correct 98 ms 13948 KB Output is correct
6 Correct 106 ms 13812 KB Output is correct
7 Correct 91 ms 13756 KB Output is correct
8 Correct 77 ms 13924 KB Output is correct
9 Correct 47 ms 12964 KB Output is correct
10 Correct 99 ms 13368 KB Output is correct
11 Correct 74 ms 13176 KB Output is correct
12 Correct 84 ms 13552 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 88 ms 13604 KB Output is correct
3 Correct 89 ms 13596 KB Output is correct
4 Correct 126 ms 13708 KB Output is correct
5 Correct 75 ms 10440 KB Output is correct
6 Correct 72 ms 10016 KB Output is correct
7 Correct 74 ms 10048 KB Output is correct
8 Correct 61 ms 7612 KB Output is correct
9 Correct 71 ms 14116 KB Output is correct
10 Correct 90 ms 14016 KB Output is correct
11 Correct 82 ms 7840 KB Output is correct
12 Correct 49 ms 8208 KB Output is correct
13 Correct 1 ms 2644 KB Output is correct
14 Correct 1 ms 2644 KB Output is correct
15 Correct 2 ms 2772 KB Output is correct
16 Correct 2 ms 2772 KB Output is correct
17 Correct 2 ms 2644 KB Output is correct
18 Correct 2 ms 2644 KB Output is correct
19 Correct 2 ms 2644 KB Output is correct
20 Correct 2 ms 2772 KB Output is correct
21 Correct 2 ms 2652 KB Output is correct
22 Correct 1 ms 2644 KB Output is correct
23 Correct 2 ms 2644 KB Output is correct
24 Correct 2 ms 2772 KB Output is correct
25 Correct 2 ms 2772 KB Output is correct
26 Correct 2 ms 2644 KB Output is correct
27 Correct 2 ms 2644 KB Output is correct
28 Correct 3 ms 2644 KB Output is correct
29 Correct 2 ms 2772 KB Output is correct
30 Correct 2 ms 2644 KB Output is correct
31 Incorrect 43 ms 4860 KB Output isn't correct
32 Halted 0 ms 0 KB -