oj.uz

Submission #1081801

# Submission time Handle Problem Language Result Execution time Memory
1081801 2024-08-30T11:14:01 Z Tymond Event Hopping (BOI22_events) C++17
20 / 100
 103 ms 16068 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){
    //cout << a << ' ' << b << ' ';
    int res = 0;
    int akt = b;
    for(int i = MAXK - 1; i >= 0; i--){
        int nr = range[i][akt];
        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[akt].fi.se < vec[a].fi.se){
       // cout << -1 << '\n';
        return -1;
    }
   // cout << res + 1 << '\n';
    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({{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 2 ms 2392 KB Output is correct
2 Correct 74 ms 15512 KB Output is correct
3 Correct 74 ms 15556 KB Output is correct
4 Correct 81 ms 15604 KB Output is correct
5 Correct 76 ms 15588 KB Output is correct
6 Correct 77 ms 15824 KB Output is correct
7 Correct 79 ms 15816 KB Output is correct
8 Incorrect 78 ms 16068 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 2396 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 2 ms 2652 KB Output is correct
4 Correct 2 ms 2564 KB Output is correct
5 Correct 2 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 2396 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 2 ms 2652 KB Output is correct
4 Correct 2 ms 2564 KB Output is correct
5 Correct 2 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 2396 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 2 ms 2652 KB Output is correct
4 Correct 2 ms 2564 KB Output is correct
5 Correct 2 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 78 ms 15556 KB Output is correct
2 Correct 77 ms 15660 KB Output is correct
3 Correct 83 ms 15556 KB Output is correct
4 Correct 77 ms 16060 KB Output is correct
5 Correct 98 ms 15972 KB Output is correct
6 Correct 103 ms 15848 KB Output is correct
7 Correct 101 ms 15808 KB Output is correct
8 Correct 98 ms 15812 KB Output is correct
9 Correct 55 ms 13768 KB Output is correct
10 Correct 85 ms 15372 KB Output is correct
11 Correct 82 ms 15300 KB Output is correct
12 Correct 86 ms 15392 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2392 KB Output is correct
2 Correct 74 ms 15512 KB Output is correct
3 Correct 74 ms 15556 KB Output is correct
4 Correct 81 ms 15604 KB Output is correct
5 Correct 76 ms 15588 KB Output is correct
6 Correct 77 ms 15824 KB Output is correct
7 Correct 79 ms 15816 KB Output is correct
8 Incorrect 78 ms 16068 KB Output isn't correct
9 Halted 0 ms 0 KB -