oj.uz

Submission #1081814

# Submission time Handle Problem Language Result Execution time Memory
1081814 2024-08-30T11:30:54 Z Tymond Event Hopping (BOI22_events) C++17
20 / 100
 99 ms 12996 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];
pii tree[2 * BASE + 7];
int range[MAXK][MAXN];
vector<pair<pii, int>> vec;
int n, q;

pii smaller(pii x, pii y){
    if(x.fi != y.fi){
        return (x.fi < y.fi ? x : y);
    }
    return (x.se < y.se ? x : y);
}

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

pii query(int v, int l, int p, int a, int b){
    if(p < a || b < l){
        return {1e9, 1e9};
    }

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

void preprocessing(){
    for(int i = 0; i < 2 * BASE + 7; i++){
        tree[i] = {1e9, 1e9};
    }

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

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

int solve(int a, int b){
    if(vec[a].fi.se >= vec[b].fi.fi && vec[a].fi.se <= vec[b].fi.se){
        return 1;
    }
    
    int res = 0;
    int akt = b;
    for(int i = MAXK - 1; i >= 0; i--){
        int nr = range[i][akt];
        if(nr == akt){
            break;
        }
        if(vec[a].fi.se >= vec[nr].fi.se){
            continue;
        }
        res += (1 << i);
        akt = nr;
        if(vec[a].fi.se >= vec[akt].fi.fi && vec[a].fi.se <= vec[akt].fi.se){
            return res + 1;
        }
    }

    return -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({{e, s}, i});
    }

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

        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 2396 KB Output is correct
2 Correct 72 ms 12520 KB Output is correct
3 Correct 75 ms 12520 KB Output is correct
4 Correct 77 ms 12484 KB Output is correct
5 Correct 76 ms 12480 KB Output is correct
6 Correct 76 ms 12468 KB Output is correct
7 Correct 77 ms 12704 KB Output is correct
8 Incorrect 67 ms 12992 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2564 KB Output is correct
3 Correct 1 ms 2652 KB Output is correct
4 Correct 2 ms 2652 KB Output is correct
5 Correct 1 ms 2652 KB Output is correct
6 Incorrect 2 ms 2652 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2564 KB Output is correct
3 Correct 1 ms 2652 KB Output is correct
4 Correct 2 ms 2652 KB Output is correct
5 Correct 1 ms 2652 KB Output is correct
6 Incorrect 2 ms 2652 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2564 KB Output is correct
3 Correct 1 ms 2652 KB Output is correct
4 Correct 2 ms 2652 KB Output is correct
5 Correct 1 ms 2652 KB Output is correct
6 Incorrect 2 ms 2652 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 79 ms 12480 KB Output is correct
2 Correct 74 ms 12488 KB Output is correct
3 Correct 78 ms 12404 KB Output is correct
4 Correct 69 ms 12996 KB Output is correct
5 Correct 95 ms 12852 KB Output is correct
6 Correct 93 ms 12660 KB Output is correct
7 Correct 99 ms 12740 KB Output is correct
8 Correct 98 ms 12736 KB Output is correct
9 Correct 55 ms 11972 KB Output is correct
10 Correct 78 ms 12228 KB Output is correct
11 Correct 93 ms 12096 KB Output is correct
12 Correct 77 ms 12228 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2396 KB Output is correct
2 Correct 72 ms 12520 KB Output is correct
3 Correct 75 ms 12520 KB Output is correct
4 Correct 77 ms 12484 KB Output is correct
5 Correct 76 ms 12480 KB Output is correct
6 Correct 76 ms 12468 KB Output is correct
7 Correct 77 ms 12704 KB Output is correct
8 Incorrect 67 ms 12992 KB Output isn't correct
9 Halted 0 ms 0 KB -