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답안 #1086570

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1086570 2024-09-11T04:50:02 Z vjudge1 Event Hopping (BOI22_events) C++17
100 / 100
 535 ms 28776 KB 
#include<bits/stdc++.h>
using namespace std;

int const N = 1e5+10;

struct interval {
    int s, e;
    interval() = default;
    interval(int a, int b) : s(a), e(b) {}
} IT[N];
bool it_cmp(interval& a, interval& b) {
    if (a.s == b.s) return a.e > b.e;
    return a.s < b.s;
}

bool it_cmp2(interval& a, interval& b) {
    if (a.e == b.e) return a.s > b.s;
    return a.e < b.e;
}

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
struct node {
    interval it; 
    int idx, meta, prior;
    node *l, *r;
    node() = default;
    node(int i) : it(IT[i]), idx(i), meta(i), prior(rng()), l(0), r(0) {}
};
using pnode = node*;

pnode rt = nullptr, rt2=nullptr;
void update(pnode u) {
    if (!u) return;
    u->meta = u->idx;
    if (u->l && IT[u->l->meta].e > IT[u->meta].e) u->meta = u->l->meta;
    if (u->r && IT[u->r->meta].e > IT[u->meta].e) u->meta = u->r->meta;
}
void update2(pnode u) {
    if (!u) return;
    u->meta = u->idx;
    if (u->l && IT[u->l->meta].s < IT[u->meta].s) u->meta = u->l->meta;
    if (u->r && IT[u->r->meta].s < IT[u->meta].s) u->meta = u->r->meta;
}

void split(pnode rt, pnode& l, pnode& r, int v, int const type = 0) {
    if (!rt) return (void)(l=r=nullptr);
    int flag = type?(v<rt->it.e):(v<rt->it.s);

    if (flag) split(rt->l, l, rt->l, v, type), r = rt;
    else split(rt->r, rt->r, r, v, type), l = rt;
    if (type) update2(rt);
    else update(rt);
}
void split(pnode rt, pnode& l, pnode& r, interval it, int const type = 0) {
    if (!rt) return (void)(l=r=nullptr);
    int flag = type?it_cmp2(it, rt->it):it_cmp(it, rt->it);

    if (flag) split(rt->l, l, rt->l, it, type), r = rt;
    else split(rt->r, rt->r, r, it, type), l = rt;
    if (type) update2(rt);
    else update(rt);
}
void join(pnode& rt, pnode l, pnode r, int const type = 0) {
    if (!l || !r) rt = l?:r;
    else if (l->prior > r->prior) join(l->r, l->r, r, type), rt = l;
    else join(r->l, l, r->l, type), rt = r;
    if (type) update2(rt);
    else update(rt);
}
void add(int idx) {
    if (rt == nullptr) {
        rt = new node(idx);
        rt2 = new node(idx);
    }
    else {
        pnode nn = new node(idx);
        pnode lv, rv;
        split(rt, lv, rv, nn->it, 0);
        join(rt, lv, nn, 0); join(rt, rt, rv, 0);

        pnode nn2 = new node(idx);
        split(rt2, lv, rv, nn2->it, 1);
        join(rt2, lv, nn2, 1); join(rt2, rt2, rv, 1);
    }
}

int sparse[18][N];
int border[18][N];
void dfs(pnode r) {
    if (!r) return;
    dfs(r->l);
    cerr << "[" << r->it.s << ", " << r->it.e << "] ";
    dfs(r->r);
}


int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);
    int n, q; cin >> n >> q;
    for (int i = 1; i <= n; ++i) {
        cin >> IT[i].s >> IT[i].e;
        add(i);
    }
    //dfs(rt); cerr << '\n';
    for (int i = 1; i <= n; ++i) {
        pnode lv, mv, rv; split(rt, lv, rv, IT[i].e);
        //dfs(lv);
        //cerr << lv->meta << ' ';
        sparse[0][i] = lv->meta;
        join(rt, lv, rv);

        split(rt2, lv, rv, IT[i].e, 1);
        split(lv, lv, mv, IT[i].s-1, 1);
        border[0][i] = mv->meta;
        join(rt2, lv, mv, 1);
        join(rt2, rt2, rv, 1);
    }
    //cerr << '\n';
    for (int b = 1; b < 18; ++b) {
        for (int i = 1; i <= n; ++i) sparse[b][i] = sparse[b-1][sparse[b-1][i]];
        for (int i = 1; i <= n; ++i) border[b][i] = border[b-1][border[b-1][i]];
    }
    for (int i = 0; i < q; ++i) {
        int a, b; cin >> a >> b;
        if (a == b) {
            cout << 0 << '\n';
            continue;
        }


        if (IT[a].e > IT[b].e) {
            cout << "impossible\n";
            continue;
        }
        else if (IT[sparse[17][a]].e < IT[b].s) {
            cout << "impossible\n";
            continue;
        }
        int st = 0;
        for (int bb = 16; ~bb; --bb) {
            int idx = sparse[bb][a];
            if (IT[idx].e < IT[b].e) {
                st += 1<<bb;
                a = idx;
            }
        }
        if (IT[a].e >= IT[b].s) {
            ++st;
            cout << st << '\n';
            continue;
        }
        if (IT[border[17][b]].s > IT[a].e) {
            cout << "impossible\n";
            continue;
        }
        for (int bb = 16; ~bb; --bb) {
            int idx = border[bb][b];
            if (IT[idx].s > IT[a].e) {
                st += 1<<bb;
                b = idx;
            }
        }
        //if (border[0][b] > IT[a].e) {
        //    cout << "impossible\n";
        //    continue;
        //}
        cout << (st+2) << '\n';
    }

}

Subtask #1
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 856 KB Output is correct
2 Correct 368 ms 28328 KB Output is correct
3 Correct 397 ms 28188 KB Output is correct
4 Correct 388 ms 28424 KB Output is correct
5 Correct 395 ms 28244 KB Output is correct
6 Correct 407 ms 28440 KB Output is correct
7 Correct 417 ms 28500 KB Output is correct
8 Correct 363 ms 28756 KB Output is correct
9 Correct 383 ms 28752 KB Output is correct
10 Correct 376 ms 28744 KB Output is correct
11 Correct 391 ms 28752 KB Output is correct
12 Correct 132 ms 27988 KB Output is correct

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 604 KB Output is correct
2 Correct 1 ms 604 KB Output is correct
3 Correct 2 ms 860 KB Output is correct
4 Correct 2 ms 872 KB Output is correct
5 Correct 2 ms 1112 KB Output is correct
6 Correct 2 ms 860 KB Output is correct
7 Correct 3 ms 860 KB Output is correct
8 Correct 1 ms 860 KB Output is correct
9 Correct 1 ms 860 KB Output is correct

Subtask #3
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 604 KB Output is correct
2 Correct 1 ms 604 KB Output is correct
3 Correct 2 ms 860 KB Output is correct
4 Correct 2 ms 872 KB Output is correct
5 Correct 2 ms 1112 KB Output is correct
6 Correct 2 ms 860 KB Output is correct
7 Correct 3 ms 860 KB Output is correct
8 Correct 1 ms 860 KB Output is correct
9 Correct 1 ms 860 KB Output is correct
10 Correct 0 ms 604 KB Output is correct
11 Correct 0 ms 604 KB Output is correct
12 Correct 2 ms 832 KB Output is correct
13 Correct 2 ms 860 KB Output is correct
14 Correct 3 ms 860 KB Output is correct
15 Correct 2 ms 860 KB Output is correct
16 Correct 2 ms 852 KB Output is correct
17 Correct 2 ms 752 KB Output is correct
18 Correct 1 ms 860 KB Output is correct
19 Correct 32 ms 3256 KB Output is correct
20 Correct 31 ms 3164 KB Output is correct
21 Correct 35 ms 3496 KB Output is correct
22 Correct 29 ms 3412 KB Output is correct
23 Correct 29 ms 3404 KB Output is correct
24 Correct 22 ms 3408 KB Output is correct
25 Correct 26 ms 3164 KB Output is correct

Subtask #4
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 604 KB Output is correct
2 Correct 1 ms 604 KB Output is correct
3 Correct 2 ms 860 KB Output is correct
4 Correct 2 ms 872 KB Output is correct
5 Correct 2 ms 1112 KB Output is correct
6 Correct 2 ms 860 KB Output is correct
7 Correct 3 ms 860 KB Output is correct
8 Correct 1 ms 860 KB Output is correct
9 Correct 1 ms 860 KB Output is correct
10 Correct 0 ms 604 KB Output is correct
11 Correct 0 ms 480 KB Output is correct
12 Correct 2 ms 860 KB Output is correct
13 Correct 2 ms 744 KB Output is correct
14 Correct 3 ms 856 KB Output is correct
15 Correct 2 ms 808 KB Output is correct
16 Correct 3 ms 860 KB Output is correct
17 Correct 2 ms 856 KB Output is correct
18 Correct 1 ms 860 KB Output is correct
19 Correct 338 ms 26456 KB Output is correct
20 Correct 343 ms 25684 KB Output is correct
21 Correct 475 ms 26440 KB Output is correct
22 Correct 375 ms 26452 KB Output is correct
23 Correct 267 ms 26448 KB Output is correct
24 Correct 386 ms 26452 KB Output is correct
25 Correct 73 ms 25976 KB Output is correct

Subtask #5
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 362 ms 28208 KB Output is correct
2 Correct 364 ms 28244 KB Output is correct
3 Correct 371 ms 28244 KB Output is correct
4 Correct 342 ms 28696 KB Output is correct
5 Correct 358 ms 28752 KB Output is correct
6 Correct 420 ms 28496 KB Output is correct
7 Correct 415 ms 28496 KB Output is correct
8 Correct 395 ms 28500 KB Output is correct
9 Correct 257 ms 26448 KB Output is correct
10 Correct 412 ms 28164 KB Output is correct
11 Correct 374 ms 27988 KB Output is correct
12 Correct 419 ms 28108 KB Output is correct

Subtask #6
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 856 KB Output is correct
2 Correct 368 ms 28328 KB Output is correct
3 Correct 397 ms 28188 KB Output is correct
4 Correct 388 ms 28424 KB Output is correct
5 Correct 395 ms 28244 KB Output is correct
6 Correct 407 ms 28440 KB Output is correct
7 Correct 417 ms 28500 KB Output is correct
8 Correct 363 ms 28756 KB Output is correct
9 Correct 383 ms 28752 KB Output is correct
10 Correct 376 ms 28744 KB Output is correct
11 Correct 391 ms 28752 KB Output is correct
12 Correct 132 ms 27988 KB Output is correct
13 Correct 1 ms 604 KB Output is correct
14 Correct 1 ms 604 KB Output is correct
15 Correct 2 ms 860 KB Output is correct
16 Correct 2 ms 872 KB Output is correct
17 Correct 2 ms 1112 KB Output is correct
18 Correct 2 ms 860 KB Output is correct
19 Correct 3 ms 860 KB Output is correct
20 Correct 1 ms 860 KB Output is correct
21 Correct 1 ms 860 KB Output is correct
22 Correct 0 ms 604 KB Output is correct
23 Correct 0 ms 604 KB Output is correct
24 Correct 2 ms 832 KB Output is correct
25 Correct 2 ms 860 KB Output is correct
26 Correct 3 ms 860 KB Output is correct
27 Correct 2 ms 860 KB Output is correct
28 Correct 2 ms 852 KB Output is correct
29 Correct 2 ms 752 KB Output is correct
30 Correct 1 ms 860 KB Output is correct
31 Correct 32 ms 3256 KB Output is correct
32 Correct 31 ms 3164 KB Output is correct
33 Correct 35 ms 3496 KB Output is correct
34 Correct 29 ms 3412 KB Output is correct
35 Correct 29 ms 3404 KB Output is correct
36 Correct 22 ms 3408 KB Output is correct
37 Correct 26 ms 3164 KB Output is correct
38 Correct 0 ms 604 KB Output is correct
39 Correct 0 ms 480 KB Output is correct
40 Correct 2 ms 860 KB Output is correct
41 Correct 2 ms 744 KB Output is correct
42 Correct 3 ms 856 KB Output is correct
43 Correct 2 ms 808 KB Output is correct
44 Correct 3 ms 860 KB Output is correct
45 Correct 2 ms 856 KB Output is correct
46 Correct 1 ms 860 KB Output is correct
47 Correct 338 ms 26456 KB Output is correct
48 Correct 343 ms 25684 KB Output is correct
49 Correct 475 ms 26440 KB Output is correct
50 Correct 375 ms 26452 KB Output is correct
51 Correct 267 ms 26448 KB Output is correct
52 Correct 386 ms 26452 KB Output is correct
53 Correct 73 ms 25976 KB Output is correct
54 Correct 362 ms 28208 KB Output is correct
55 Correct 364 ms 28244 KB Output is correct
56 Correct 371 ms 28244 KB Output is correct
57 Correct 342 ms 28696 KB Output is correct
58 Correct 358 ms 28752 KB Output is correct
59 Correct 420 ms 28496 KB Output is correct
60 Correct 415 ms 28496 KB Output is correct
61 Correct 395 ms 28500 KB Output is correct
62 Correct 257 ms 26448 KB Output is correct
63 Correct 412 ms 28164 KB Output is correct
64 Correct 374 ms 27988 KB Output is correct
65 Correct 419 ms 28108 KB Output is correct
66 Correct 0 ms 604 KB Output is correct
67 Correct 344 ms 28256 KB Output is correct
68 Correct 366 ms 28244 KB Output is correct
69 Correct 388 ms 28284 KB Output is correct
70 Correct 383 ms 28244 KB Output is correct
71 Correct 379 ms 28472 KB Output is correct
72 Correct 384 ms 28500 KB Output is correct
73 Correct 360 ms 28776 KB Output is correct
74 Correct 337 ms 28752 KB Output is correct
75 Correct 374 ms 28756 KB Output is correct
76 Correct 388 ms 28672 KB Output is correct
77 Correct 133 ms 27988 KB Output is correct
78 Correct 0 ms 600 KB Output is correct
79 Correct 2 ms 860 KB Output is correct
80 Correct 2 ms 860 KB Output is correct
81 Correct 2 ms 860 KB Output is correct
82 Correct 2 ms 860 KB Output is correct
83 Correct 2 ms 860 KB Output is correct
84 Correct 2 ms 856 KB Output is correct
85 Correct 1 ms 860 KB Output is correct
86 Correct 30 ms 3164 KB Output is correct
87 Correct 29 ms 3300 KB Output is correct
88 Correct 34 ms 3408 KB Output is correct
89 Correct 28 ms 3420 KB Output is correct
90 Correct 30 ms 3408 KB Output is correct
91 Correct 22 ms 3408 KB Output is correct
92 Correct 27 ms 2892 KB Output is correct
93 Correct 323 ms 26448 KB Output is correct
94 Correct 336 ms 25680 KB Output is correct
95 Correct 466 ms 26448 KB Output is correct
96 Correct 360 ms 26452 KB Output is correct
97 Correct 259 ms 26404 KB Output is correct
98 Correct 377 ms 26452 KB Output is correct
99 Correct 68 ms 25936 KB Output is correct
100 Correct 411 ms 28428 KB Output is correct
101 Correct 410 ms 28500 KB Output is correct
102 Correct 397 ms 28504 KB Output is correct
103 Correct 415 ms 27988 KB Output is correct
104 Correct 387 ms 27912 KB Output is correct
105 Correct 413 ms 28192 KB Output is correct
106 Correct 374 ms 27732 KB Output is correct
107 Correct 392 ms 27728 KB Output is correct
108 Correct 511 ms 28336 KB Output is correct
109 Correct 487 ms 28752 KB Output is correct
110 Correct 535 ms 28372 KB Output is correct
111 Correct 528 ms 28360 KB Output is correct