oj.uz

Submission #1081790

# Submission time Handle Problem Language Result Execution time Memory
1081790 2024-08-30T10:52:58 Z Tymond Event Hopping (BOI22_events) C++17
20 / 100
 811 ms 30220 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
#define fi first
#define se second
#define vi vector<int>
#define vll vector<long long>
#define pii pair<int, int>
#define pll pair<long long, long long>
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());
inline int rand(int l,int r){return uniform_int_distribution<int>(l, r)(rng);}
inline ll rand(ll l,ll r){return uniform_int_distribution<ll>(l, r)(rng64);}
#ifdef DEBUG
auto&operator<<(auto&o,pair<auto,auto>p){return o<<"("<<p.first<<", "<<p.second<<")";}
auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<","+!i++<<e;return o<<"}";}
#define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(X)
#else
#define debug(...){}
#endif

struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};

const int MAXN = 1e5 + 7;
const int BASE = (1 << 17);
const int MAXK = 20;
int pos[MAXN];
int tree[MAXK][2 * BASE + 7];
int range[MAXK][MAXN];
vector<pair<pii, int>> vec;
int n, q;

void upd(int k, int ind, int val){
    ind += BASE;
    tree[k][ind] = val;
    ind /= 2;
    while(ind > 0){
        tree[k][ind] = max(tree[k][2 * ind], tree[k][2 * ind + 1]);
        ind /= 2;
    }
}

int query(int v, int l, int p, int k, int a, int b){
    if(p < a || b < l){
        return 0;
    }

    if(a <= l && p <= b){
        return tree[k][v];
    }
    int mid = (l + p) / 2;
    return max(query(2 * v, l, mid, k, a, b), query(2 * v + 1, mid + 1, p, k, a, b));
}

void preprocessing(){
    //cout << "RANGES\n";
    for(int i = 0; i < n; i++){
        int l = i;
        int p = n - 1;
        int s;
        while(l < p){
            s = (l + p + 1) / 2;
            if(vec[i].fi.se < vec[s].fi.fi){
                p = s - 1;
            }else{
                l = s;
            }
        }
        //cout << i << ' ' << l << '\n';
        range[0][i] = l;
        upd(0, i, l);
    }

    for(int k = 1; k < MAXK; k++){
        for(int i = 0; i < n; i++){
            range[k][i] = query(1, 0, BASE - 1, k - 1, i, range[k - 1][i]);
            upd(k, i, range[k][i]);
        }
    }
}

int solve(int a, int b){
    if(range[19][a] < b){
        return -1;
    }

    int res = 0;
    int akt = a;
    for(int i = MAXK - 1; i >= 0; i--){
        int nr = query(1, 0, BASE - 1, i, a,akt);
        if(nr >= b){
            continue;
        }
        res += (1 << i);
        akt = nr;
    }

    return res + 1;
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    
    cin >> n >> q;
    for(int i = 1; i <= n; i++){
        int s,e;
        cin >> s >> e;
        vec.pb({{s, e}, i});
    }

    sort(all(vec));
    for(int i = 0; i < n; i++){
        pos[vec[i].se] = i;
    }

    preprocessing();

    /*for(auto ele : vec){
        cout << ele.fi.fi << ' ' << ele.fi.se << '\n';
    }

    for(int i = 0; i < n; i++){
        for(int j = 0; j < MAXK / 2; j++){
            cout << range[j][i] << ' ';
        }
        cout << '\n';
    }*/

    while(q--){
        int s, e;
        cin >> s >> e;
        s = pos[s];
        e = pos[e];
       // cout << "PYTANIE: " << s << ' ' << e << '\n';
        if(s == e){
            cout << 0 << '\n';
            continue;
        }

        if(s > e){
            if(vec[e].fi.se >= vec[s].fi.se){
                cout << 1 << '\n';
            }else{
                cout << "impossible\n";
            }
            continue;
        }
        if(vec[s].fi.se > vec[e].fi.se){
            cout << "impossible\n";
            continue;
        }

        int ans = solve(s, e);
        if(ans == -1){
            cout << "impossible\n";
        }else{
            cout << ans << '\n';
        }
    }

    return 0;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1116 KB Output is correct
2 Correct 578 ms 29964 KB Output is correct
3 Correct 766 ms 29888 KB Output is correct
4 Correct 728 ms 29896 KB Output is correct
5 Incorrect 738 ms 29892 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1116 KB Output is correct
2 Correct 1 ms 1116 KB Output is correct
3 Correct 4 ms 1372 KB Output is correct
4 Correct 4 ms 1372 KB Output is correct
5 Incorrect 4 ms 1612 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1116 KB Output is correct
2 Correct 1 ms 1116 KB Output is correct
3 Correct 4 ms 1372 KB Output is correct
4 Correct 4 ms 1372 KB Output is correct
5 Incorrect 4 ms 1612 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1116 KB Output is correct
2 Correct 1 ms 1116 KB Output is correct
3 Correct 4 ms 1372 KB Output is correct
4 Correct 4 ms 1372 KB Output is correct
5 Incorrect 4 ms 1612 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 597 ms 29912 KB Output is correct
2 Correct 811 ms 29876 KB Output is correct
3 Correct 752 ms 29812 KB Output is correct
4 Correct 345 ms 30220 KB Output is correct
5 Correct 573 ms 30152 KB Output is correct
6 Correct 681 ms 29888 KB Output is correct
7 Correct 593 ms 29892 KB Output is correct
8 Correct 498 ms 29996 KB Output is correct
9 Correct 391 ms 28100 KB Output is correct
10 Correct 667 ms 29892 KB Output is correct
11 Correct 580 ms 29380 KB Output is correct
12 Correct 682 ms 29640 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1116 KB Output is correct
2 Correct 578 ms 29964 KB Output is correct
3 Correct 766 ms 29888 KB Output is correct
4 Correct 728 ms 29896 KB Output is correct
5 Incorrect 738 ms 29892 KB Output isn't correct
6 Halted 0 ms 0 KB -