oj.uz

Submission #714333

# Submission time Handle Problem Language Result Execution time Memory
714333 2023-03-24T09:00:51 Z Mamedov Event Hopping (BOI22_events) C++17
100 / 100
 275 ms 29316 KB 
#pragma GCC optimize ("O3")
#include <bits/stdc++.h>
#define pii pair<int, int>
#define piii pair<pii, int>
#define vi vector<int>
#define vll vector<ll>
#define vvi vector<vi>
#define vpii vector<pii>
#define vvpii vector<vpii>
#define f first
#define s second
#define oo 1000000001
#define eb emplace_back
#define pb push_back
#define mpr make_pair
#define size(v) (int)v.size()
#define ln '\n'
#define ull unsigned long long
#define ll long long
#define all(v) v.begin(), v.end()

using namespace std;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int up = 2e5 + 5;
int LOG[up];

void preClc() {
  LOG[1] = 0;
  for (int i = 2; i < up; ++i) {
    LOG[i] = LOG[i >> 1] + 1;
  }
}

struct Stable {
  int n, lg;
  vector<int>v;
  vector<vector<int>>stMin;
  Stable(int N, int LG, vector<int> &arr) {
    n = N;
    lg = LG;
    v = arr;
    stMin.resize(lg, vector<int>(n));
    for (int i = 0; i < n; ++i) {
      stMin[0][i] = i;
    }
  }
  void buildMin() {
    for (int i = 1; i < lg; ++i) {
      for (int j = 0; j + (1 << i) <= n; ++j) {
        if (v[stMin[i - 1][j]] <= v[stMin[i - 1][j + (1 << (i - 1))]]) {
          stMin[i][j] = stMin[i - 1][j];
        } else {
          stMin[i][j] = stMin[i - 1][j + (1 << (i - 1))];
        }
      }
    }
  }
  int getMin(int l, int r) {
    if (l > r) return -1;
    int sz = r - l + 1;
    int j = LOG[sz];
    if (v[stMin[j][l]] <=  v[stMin[j][r - (1 << j) + 1]]) {
      return stMin[j][l];
    } else {
      return stMin[j][r - (1 << j) + 1];
    }
  }
}; // Call preClc() and assign up

void solve() {
  int n, q;
  cin >> n >> q;
  vpii e(n + 1);
  vi compress;
  for (int i = 1; i <= n; ++i) {
    cin >> e[i].f >> e[i].s;
    compress.eb(e[i].f);
    compress.eb(e[i].s);
  }
  sort(all(compress));
  compress.erase(unique(all(compress)), compress.end());
  for (int i = 1; i <= n; ++i) {
    e[i].f = lower_bound(all(compress), e[i].f) - compress.begin();
    e[i].s = lower_bound(all(compress), e[i].s) - compress.begin();
  }
  int sz = size(compress);
  vi minStart(sz, sz);
  vi who(sz, 0);
  for (int i = 1; i <= n; ++i) {
    if (minStart[e[i].s] > e[i].f) {
      minStart[e[i].s] = e[i].f;
      who[e[i].s] = i;
    }
  }

  Stable rmq(sz, 19, minStart);
  rmq.buildMin();

  const int lg = 18;
  vvi prev(lg, vi(n + 1));

  for (int i = 1; i <= n; ++i) {
    prev[0][i] = who[rmq.getMin(e[i].f, e[i].s)];
    if (prev[0][i] == i) prev[0][i] = 0;
  }

  for (int i = 1; i < lg; ++i) {
    for (int j = 1; j <= n; ++j) {
      prev[i][j] = prev[i - 1][prev[i - 1][j]];
    }
  }
  for (int i = 0; i < q; ++i) {
    int st, ed;
    cin >> st >> ed;

    if (e[st].s > e[ed].s) {
      cout << "impossible\n";
    } else if (st == ed) {
      cout << 0 << ln;
    } else if (e[st].s >= e[ed].f && e[st].s <= e[ed].s) {
      cout << 1 << ln;
    } else {
      int res = 0;
      for (int i = lg - 1; i >= 0; --i) {
        if (e[prev[i][ed]].f > e[st].s) {
          res += (1 << i);
          ed = prev[i][ed];
        }
      }
      ed = prev[0][ed];
      ++res;

      if (ed == 0) {
        cout << "impossible\n";
      } else {
        cout << res + 1 << ln;
      }
    }
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  preClc();
  solve();
  return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1108 KB Output is correct
2 Correct 202 ms 19320 KB Output is correct
3 Correct 224 ms 19328 KB Output is correct
4 Correct 271 ms 20008 KB Output is correct
5 Correct 230 ms 21024 KB Output is correct
6 Correct 239 ms 21824 KB Output is correct
7 Correct 223 ms 22048 KB Output is correct
8 Correct 219 ms 29180 KB Output is correct
9 Correct 225 ms 29184 KB Output is correct
10 Correct 261 ms 20376 KB Output is correct
11 Correct 242 ms 23828 KB Output is correct
12 Correct 178 ms 20664 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1108 KB Output is correct
2 Correct 1 ms 1084 KB Output is correct
3 Correct 2 ms 1236 KB Output is correct
4 Correct 1 ms 1236 KB Output is correct
5 Correct 1 ms 1236 KB Output is correct
6 Correct 2 ms 1236 KB Output is correct
7 Correct 2 ms 1364 KB Output is correct
8 Correct 1 ms 1364 KB Output is correct
9 Correct 1 ms 1108 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1108 KB Output is correct
2 Correct 1 ms 1084 KB Output is correct
3 Correct 2 ms 1236 KB Output is correct
4 Correct 1 ms 1236 KB Output is correct
5 Correct 1 ms 1236 KB Output is correct
6 Correct 2 ms 1236 KB Output is correct
7 Correct 2 ms 1364 KB Output is correct
8 Correct 1 ms 1364 KB Output is correct
9 Correct 1 ms 1108 KB Output is correct
10 Correct 1 ms 1108 KB Output is correct
11 Correct 1 ms 1108 KB Output is correct
12 Correct 2 ms 1236 KB Output is correct
13 Correct 2 ms 1236 KB Output is correct
14 Correct 2 ms 1236 KB Output is correct
15 Correct 2 ms 1236 KB Output is correct
16 Correct 2 ms 1364 KB Output is correct
17 Correct 3 ms 1364 KB Output is correct
18 Correct 1 ms 1108 KB Output is correct
19 Correct 146 ms 2632 KB Output is correct
20 Correct 147 ms 2620 KB Output is correct
21 Correct 152 ms 2816 KB Output is correct
22 Correct 172 ms 2912 KB Output is correct
23 Correct 138 ms 3116 KB Output is correct
24 Correct 135 ms 3148 KB Output is correct
25 Correct 144 ms 2764 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1108 KB Output is correct
2 Correct 1 ms 1084 KB Output is correct
3 Correct 2 ms 1236 KB Output is correct
4 Correct 1 ms 1236 KB Output is correct
5 Correct 1 ms 1236 KB Output is correct
6 Correct 2 ms 1236 KB Output is correct
7 Correct 2 ms 1364 KB Output is correct
8 Correct 1 ms 1364 KB Output is correct
9 Correct 1 ms 1108 KB Output is correct
10 Correct 1 ms 1108 KB Output is correct
11 Correct 1 ms 1108 KB Output is correct
12 Correct 2 ms 1236 KB Output is correct
13 Correct 2 ms 1236 KB Output is correct
14 Correct 2 ms 1236 KB Output is correct
15 Correct 2 ms 1236 KB Output is correct
16 Correct 2 ms 1364 KB Output is correct
17 Correct 2 ms 1364 KB Output is correct
18 Correct 1 ms 1108 KB Output is correct
19 Correct 68 ms 18692 KB Output is correct
20 Correct 65 ms 19096 KB Output is correct
21 Correct 78 ms 18736 KB Output is correct
22 Correct 74 ms 22576 KB Output is correct
23 Correct 77 ms 28048 KB Output is correct
24 Correct 80 ms 27996 KB Output is correct
25 Correct 29 ms 10728 KB Output is correct

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 206 ms 19324 KB Output is correct
2 Correct 231 ms 19272 KB Output is correct
3 Correct 264 ms 20120 KB Output is correct
4 Correct 237 ms 29316 KB Output is correct
5 Correct 266 ms 20500 KB Output is correct
6 Correct 275 ms 28896 KB Output is correct
7 Correct 262 ms 28848 KB Output is correct
8 Correct 234 ms 28980 KB Output is correct
9 Correct 80 ms 28084 KB Output is correct
10 Correct 237 ms 28664 KB Output is correct
11 Correct 221 ms 28252 KB Output is correct
12 Correct 233 ms 28480 KB Output is correct

Subtask #6
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1108 KB Output is correct
2 Correct 202 ms 19320 KB Output is correct
3 Correct 224 ms 19328 KB Output is correct
4 Correct 271 ms 20008 KB Output is correct
5 Correct 230 ms 21024 KB Output is correct
6 Correct 239 ms 21824 KB Output is correct
7 Correct 223 ms 22048 KB Output is correct
8 Correct 219 ms 29180 KB Output is correct
9 Correct 225 ms 29184 KB Output is correct
10 Correct 261 ms 20376 KB Output is correct
11 Correct 242 ms 23828 KB Output is correct
12 Correct 178 ms 20664 KB Output is correct
13 Correct 1 ms 1108 KB Output is correct
14 Correct 1 ms 1084 KB Output is correct
15 Correct 2 ms 1236 KB Output is correct
16 Correct 1 ms 1236 KB Output is correct
17 Correct 1 ms 1236 KB Output is correct
18 Correct 2 ms 1236 KB Output is correct
19 Correct 2 ms 1364 KB Output is correct
20 Correct 1 ms 1364 KB Output is correct
21 Correct 1 ms 1108 KB Output is correct
22 Correct 1 ms 1108 KB Output is correct
23 Correct 1 ms 1108 KB Output is correct
24 Correct 2 ms 1236 KB Output is correct
25 Correct 2 ms 1236 KB Output is correct
26 Correct 2 ms 1236 KB Output is correct
27 Correct 2 ms 1236 KB Output is correct
28 Correct 2 ms 1364 KB Output is correct
29 Correct 3 ms 1364 KB Output is correct
30 Correct 1 ms 1108 KB Output is correct
31 Correct 146 ms 2632 KB Output is correct
32 Correct 147 ms 2620 KB Output is correct
33 Correct 152 ms 2816 KB Output is correct
34 Correct 172 ms 2912 KB Output is correct
35 Correct 138 ms 3116 KB Output is correct
36 Correct 135 ms 3148 KB Output is correct
37 Correct 144 ms 2764 KB Output is correct
38 Correct 1 ms 1108 KB Output is correct
39 Correct 1 ms 1108 KB Output is correct
40 Correct 2 ms 1236 KB Output is correct
41 Correct 2 ms 1236 KB Output is correct
42 Correct 2 ms 1236 KB Output is correct
43 Correct 2 ms 1236 KB Output is correct
44 Correct 2 ms 1364 KB Output is correct
45 Correct 2 ms 1364 KB Output is correct
46 Correct 1 ms 1108 KB Output is correct
47 Correct 68 ms 18692 KB Output is correct
48 Correct 65 ms 19096 KB Output is correct
49 Correct 78 ms 18736 KB Output is correct
50 Correct 74 ms 22576 KB Output is correct
51 Correct 77 ms 28048 KB Output is correct
52 Correct 80 ms 27996 KB Output is correct
53 Correct 29 ms 10728 KB Output is correct
54 Correct 206 ms 19324 KB Output is correct
55 Correct 231 ms 19272 KB Output is correct
56 Correct 264 ms 20120 KB Output is correct
57 Correct 237 ms 29316 KB Output is correct
58 Correct 266 ms 20500 KB Output is correct
59 Correct 275 ms 28896 KB Output is correct
60 Correct 262 ms 28848 KB Output is correct
61 Correct 234 ms 28980 KB Output is correct
62 Correct 80 ms 28084 KB Output is correct
63 Correct 237 ms 28664 KB Output is correct
64 Correct 221 ms 28252 KB Output is correct
65 Correct 233 ms 28480 KB Output is correct
66 Correct 1 ms 1108 KB Output is correct
67 Correct 212 ms 19996 KB Output is correct
68 Correct 225 ms 19980 KB Output is correct
69 Correct 272 ms 19924 KB Output is correct
70 Correct 227 ms 20920 KB Output is correct
71 Correct 233 ms 21856 KB Output is correct
72 Correct 222 ms 22080 KB Output is correct
73 Correct 212 ms 29128 KB Output is correct
74 Correct 215 ms 29136 KB Output is correct
75 Correct 248 ms 20436 KB Output is correct
76 Correct 232 ms 23936 KB Output is correct
77 Correct 178 ms 20508 KB Output is correct
78 Correct 1 ms 1108 KB Output is correct
79 Correct 2 ms 1256 KB Output is correct
80 Correct 2 ms 1236 KB Output is correct
81 Correct 2 ms 1236 KB Output is correct
82 Correct 2 ms 1248 KB Output is correct
83 Correct 2 ms 1384 KB Output is correct
84 Correct 2 ms 1380 KB Output is correct
85 Correct 1 ms 1124 KB Output is correct
86 Correct 150 ms 3276 KB Output is correct
87 Correct 143 ms 3080 KB Output is correct
88 Correct 152 ms 3400 KB Output is correct
89 Correct 143 ms 3452 KB Output is correct
90 Correct 138 ms 3692 KB Output is correct
91 Correct 135 ms 3700 KB Output is correct
92 Correct 143 ms 3404 KB Output is correct
93 Correct 67 ms 19392 KB Output is correct
94 Correct 69 ms 19772 KB Output is correct
95 Correct 72 ms 19400 KB Output is correct
96 Correct 73 ms 22600 KB Output is correct
97 Correct 75 ms 28096 KB Output is correct
98 Correct 78 ms 28012 KB Output is correct
99 Correct 29 ms 10824 KB Output is correct
100 Correct 243 ms 28868 KB Output is correct
101 Correct 238 ms 28968 KB Output is correct
102 Correct 242 ms 28972 KB Output is correct
103 Correct 222 ms 28464 KB Output is correct
104 Correct 221 ms 28224 KB Output is correct
105 Correct 223 ms 28504 KB Output is correct
106 Correct 227 ms 18268 KB Output is correct
107 Correct 253 ms 20544 KB Output is correct
108 Correct 221 ms 20276 KB Output is correct
109 Correct 211 ms 20296 KB Output is correct
110 Correct 219 ms 28772 KB Output is correct
111 Correct 213 ms 28740 KB Output is correct