oj.uz

Submission #722710

# Submission time Handle Problem Language Result Execution time Memory
722710 2023-04-12T17:18:21 Z dxz05 Event Hopping (BOI22_events) C++17
100 / 100
 612 ms 27984 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
#define all(x) (x).begin(), (x).end()
#define MP make_pair
const int N = 100500;

template <typename T>
struct SegmentTree{
    int n = 0;
    vector<T> tree;

    T neutral_element = make_pair(1e9, -1); // e.g. 0 for sum, INF for min ...

    SegmentTree(){};
    SegmentTree(int _n){
        n = _n;
        tree.assign(n * 4 + 5, neutral_element);
    }

    inline T combine(T lf, T rg){
        return min(lf, rg); // change it
    }

    inline void build(int v, int tl, int tr, const vector<T> &a){
        if (tl == tr){
            tree[v] = a[tl];
            return;
        }
        int tm = (tl + tr) >> 1;
        build(v << 1, tl, tm, a);
        build(v << 1 | 1, tm + 1, tr, a);
        tree[v] = combine(tree[v << 1], tree[v << 1 | 1]);
    }

    inline void init(const vector<T> &a){
        n = (int)a.size();
        tree.assign(n * 4 + 5, neutral_element);
        build(1, 0, n - 1, a);
    }

    inline void update(int v, int tl, int tr, int pos, T val){
        if (tl == tr){
            tree[v] = min(tree[v], val); // pay attention!
            return;
        }
        int tm = (tl + tr) >> 1;
        if (pos <= tm){
            update(v << 1, tl, tm, pos, val);
        } else {
            update(v << 1 | 1, tm + 1, tr, pos, val);
        }
        tree[v] = combine(tree[v << 1], tree[v << 1 | 1]);
    }

    inline void update(int pos, T val){
        update(1, 0, n - 1, pos, val);
    }

    inline T get(int v, int tl, int tr, int l, int r){
        if (l <= tl && tr <= r) return tree[v];
        if (tl > r || tr < l) return neutral_element;
        int tm = (tl + tr) >> 1;
        return combine(get(v << 1, tl, tm, l, r), get(v << 1 | 1, tm + 1, tr, l, r));
    }

    inline T get(int l, int r){
        return get(1, 0, n - 1, l, r);
    }

};

int f[N][18];
int l[N], r[N];

bool can_switch(int i, int j){
    return l[j] <= r[i] && r[i] <= r[j];
}

void solve(){
    int n, q;
    cin >> n >> q;

    map<int, int> mp;
    for (int i = 0; i < n; i++){
        cin >> l[i] >> r[i];
        mp[l[i]], mp[r[i]];
    }

    int z = 0;
    for (auto &now : mp) now.second = z++;

    SegmentTree<pair<int, int>> st(n * 2);
    for (int i = 0; i < n; i++) {
        st.update(mp[r[i]], make_pair(mp[l[i]], i));
    }

    for (int i = 0; i < n; i++){
        int j = st.get(mp[l[i]], mp[r[i]]).second;
        f[i][0] = (j != -1 && l[j] < l[i] ? j : -1);
    }

    for (int j = 1; j < 18; j++){
        for (int i = 0; i < n; i++){
            int mid = f[i][j - 1];
            f[i][j] = (mid != -1 ? f[mid][j - 1] : -1);
        }
    }

    while (q--){
        int x, y;
        cin >> x >> y;
        --x, --y;
        if (x == y){
            cout << 0 << endl;
            continue;
        }
        if (can_switch(x, y)){
            cout << 1 << endl;
            continue;
        }

        int cnt = 2;
        for (int i = 17; i >= 0; i--){
            int to = f[y][i];
            if (to != -1 && l[to] > r[x]){
                cnt += 1 << i;
                y = to;
            }
        }

        y = f[y][0];

        if (y != -1 && can_switch(x, y)){
            cout << cnt << endl;
        } else {
            cout << "impossible" << endl;
        }
    }

}

int main() {
    ios_base::sync_with_stdio(false);

#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    solve();

    return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 342 ms 19768 KB Output is correct
3 Correct 406 ms 19904 KB Output is correct
4 Correct 434 ms 19844 KB Output is correct
5 Correct 401 ms 20312 KB Output is correct
6 Correct 457 ms 20844 KB Output is correct
7 Correct 393 ms 21060 KB Output is correct
8 Correct 429 ms 25068 KB Output is correct
9 Correct 423 ms 25096 KB Output is correct
10 Correct 483 ms 20216 KB Output is correct
11 Correct 452 ms 24812 KB Output is correct
12 Correct 289 ms 22472 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 2 ms 468 KB Output is correct
4 Correct 2 ms 464 KB Output is correct
5 Correct 2 ms 456 KB Output is correct
6 Correct 2 ms 468 KB Output is correct
7 Correct 3 ms 564 KB Output is correct
8 Correct 2 ms 596 KB Output is correct
9 Correct 1 ms 480 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 2 ms 468 KB Output is correct
4 Correct 2 ms 464 KB Output is correct
5 Correct 2 ms 456 KB Output is correct
6 Correct 2 ms 468 KB Output is correct
7 Correct 3 ms 564 KB Output is correct
8 Correct 2 ms 596 KB Output is correct
9 Correct 1 ms 480 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 2 ms 548 KB Output is correct
13 Correct 2 ms 468 KB Output is correct
14 Correct 2 ms 468 KB Output is correct
15 Correct 2 ms 468 KB Output is correct
16 Correct 2 ms 468 KB Output is correct
17 Correct 2 ms 516 KB Output is correct
18 Correct 1 ms 468 KB Output is correct
19 Correct 148 ms 1864 KB Output is correct
20 Correct 164 ms 2168 KB Output is correct
21 Correct 151 ms 3020 KB Output is correct
22 Correct 151 ms 3064 KB Output is correct
23 Correct 160 ms 3092 KB Output is correct
24 Correct 142 ms 3128 KB Output is correct
25 Correct 149 ms 2724 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 2 ms 468 KB Output is correct
4 Correct 2 ms 464 KB Output is correct
5 Correct 2 ms 456 KB Output is correct
6 Correct 2 ms 468 KB Output is correct
7 Correct 3 ms 564 KB Output is correct
8 Correct 2 ms 596 KB Output is correct
9 Correct 1 ms 480 KB Output is correct
10 Correct 1 ms 328 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 3 ms 468 KB Output is correct
13 Correct 3 ms 468 KB Output is correct
14 Correct 2 ms 468 KB Output is correct
15 Correct 2 ms 452 KB Output is correct
16 Correct 3 ms 596 KB Output is correct
17 Correct 2 ms 468 KB Output is correct
18 Correct 1 ms 468 KB Output is correct
19 Correct 225 ms 19220 KB Output is correct
20 Correct 256 ms 19160 KB Output is correct
21 Correct 242 ms 19104 KB Output is correct
22 Correct 239 ms 20916 KB Output is correct
23 Correct 315 ms 23964 KB Output is correct
24 Correct 426 ms 23876 KB Output is correct
25 Correct 61 ms 14488 KB Output is correct

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 364 ms 19836 KB Output is correct
2 Correct 360 ms 19896 KB Output is correct
3 Correct 453 ms 19852 KB Output is correct
4 Correct 412 ms 24928 KB Output is correct
5 Correct 404 ms 20264 KB Output is correct
6 Correct 591 ms 27628 KB Output is correct
7 Correct 531 ms 27508 KB Output is correct
8 Correct 547 ms 27752 KB Output is correct
9 Correct 308 ms 25684 KB Output is correct
10 Correct 515 ms 27220 KB Output is correct
11 Correct 595 ms 27092 KB Output is correct
12 Correct 522 ms 27276 KB Output is correct

Subtask #6
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 342 ms 19768 KB Output is correct
3 Correct 406 ms 19904 KB Output is correct
4 Correct 434 ms 19844 KB Output is correct
5 Correct 401 ms 20312 KB Output is correct
6 Correct 457 ms 20844 KB Output is correct
7 Correct 393 ms 21060 KB Output is correct
8 Correct 429 ms 25068 KB Output is correct
9 Correct 423 ms 25096 KB Output is correct
10 Correct 483 ms 20216 KB Output is correct
11 Correct 452 ms 24812 KB Output is correct
12 Correct 289 ms 22472 KB Output is correct
13 Correct 1 ms 328 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 2 ms 468 KB Output is correct
16 Correct 2 ms 464 KB Output is correct
17 Correct 2 ms 456 KB Output is correct
18 Correct 2 ms 468 KB Output is correct
19 Correct 3 ms 564 KB Output is correct
20 Correct 2 ms 596 KB Output is correct
21 Correct 1 ms 480 KB Output is correct
22 Correct 1 ms 340 KB Output is correct
23 Correct 1 ms 340 KB Output is correct
24 Correct 2 ms 548 KB Output is correct
25 Correct 2 ms 468 KB Output is correct
26 Correct 2 ms 468 KB Output is correct
27 Correct 2 ms 468 KB Output is correct
28 Correct 2 ms 468 KB Output is correct
29 Correct 2 ms 516 KB Output is correct
30 Correct 1 ms 468 KB Output is correct
31 Correct 148 ms 1864 KB Output is correct
32 Correct 164 ms 2168 KB Output is correct
33 Correct 151 ms 3020 KB Output is correct
34 Correct 151 ms 3064 KB Output is correct
35 Correct 160 ms 3092 KB Output is correct
36 Correct 142 ms 3128 KB Output is correct
37 Correct 149 ms 2724 KB Output is correct
38 Correct 1 ms 328 KB Output is correct
39 Correct 1 ms 212 KB Output is correct
40 Correct 3 ms 468 KB Output is correct
41 Correct 3 ms 468 KB Output is correct
42 Correct 2 ms 468 KB Output is correct
43 Correct 2 ms 452 KB Output is correct
44 Correct 3 ms 596 KB Output is correct
45 Correct 2 ms 468 KB Output is correct
46 Correct 1 ms 468 KB Output is correct
47 Correct 225 ms 19220 KB Output is correct
48 Correct 256 ms 19160 KB Output is correct
49 Correct 242 ms 19104 KB Output is correct
50 Correct 239 ms 20916 KB Output is correct
51 Correct 315 ms 23964 KB Output is correct
52 Correct 426 ms 23876 KB Output is correct
53 Correct 61 ms 14488 KB Output is correct
54 Correct 364 ms 19836 KB Output is correct
55 Correct 360 ms 19896 KB Output is correct
56 Correct 453 ms 19852 KB Output is correct
57 Correct 412 ms 24928 KB Output is correct
58 Correct 404 ms 20264 KB Output is correct
59 Correct 591 ms 27628 KB Output is correct
60 Correct 531 ms 27508 KB Output is correct
61 Correct 547 ms 27752 KB Output is correct
62 Correct 308 ms 25684 KB Output is correct
63 Correct 515 ms 27220 KB Output is correct
64 Correct 595 ms 27092 KB Output is correct
65 Correct 522 ms 27276 KB Output is correct
66 Correct 1 ms 212 KB Output is correct
67 Correct 363 ms 22772 KB Output is correct
68 Correct 388 ms 22808 KB Output is correct
69 Correct 375 ms 22768 KB Output is correct
70 Correct 410 ms 23256 KB Output is correct
71 Correct 418 ms 23752 KB Output is correct
72 Correct 382 ms 23848 KB Output is correct
73 Correct 422 ms 27984 KB Output is correct
74 Correct 388 ms 27948 KB Output is correct
75 Correct 358 ms 23212 KB Output is correct
76 Correct 411 ms 25084 KB Output is correct
77 Correct 244 ms 22504 KB Output is correct
78 Correct 1 ms 340 KB Output is correct
79 Correct 2 ms 468 KB Output is correct
80 Correct 2 ms 516 KB Output is correct
81 Correct 2 ms 468 KB Output is correct
82 Correct 2 ms 460 KB Output is correct
83 Correct 2 ms 600 KB Output is correct
84 Correct 2 ms 596 KB Output is correct
85 Correct 1 ms 468 KB Output is correct
86 Correct 154 ms 2824 KB Output is correct
87 Correct 154 ms 2804 KB Output is correct
88 Correct 151 ms 2916 KB Output is correct
89 Correct 158 ms 3016 KB Output is correct
90 Correct 170 ms 3180 KB Output is correct
91 Correct 163 ms 3176 KB Output is correct
92 Correct 145 ms 2828 KB Output is correct
93 Correct 208 ms 21196 KB Output is correct
94 Correct 220 ms 20236 KB Output is correct
95 Correct 248 ms 20940 KB Output is correct
96 Correct 235 ms 22732 KB Output is correct
97 Correct 291 ms 25688 KB Output is correct
98 Correct 414 ms 25660 KB Output is correct
99 Correct 64 ms 15568 KB Output is correct
100 Correct 602 ms 27604 KB Output is correct
101 Correct 485 ms 27596 KB Output is correct
102 Correct 470 ms 27768 KB Output is correct
103 Correct 497 ms 27212 KB Output is correct
104 Correct 469 ms 26964 KB Output is correct
105 Correct 479 ms 27160 KB Output is correct
106 Correct 331 ms 20984 KB Output is correct
107 Correct 388 ms 22196 KB Output is correct
108 Correct 364 ms 22860 KB Output is correct
109 Correct 369 ms 22860 KB Output is correct
110 Correct 612 ms 27456 KB Output is correct
111 Correct 485 ms 27500 KB Output is correct