oj.uz

Submission #949621

# Submission time Handle Problem Language Result Execution time Memory
949621 2024-03-19T12:51:56 Z sysia Event Hopping (BOI22_events) C++17
30 / 100
 392 ms 46792 KB 
//Sylwia Sapkowska
#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
using namespace std;

void __print(int x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << "'" << x << "'";}
void __print(const char *x) {cerr << '"' << x << '"';}
void __print(const string &x) {cerr << '"' << x << '"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef LOCAL
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

#define int long long
typedef pair<int, int> T;
const int oo = 1e18, oo2 = 1e9+7, K = 20;
const int mod = 998244353;

void solve(){
    int n, q; cin >> n >> q;
    vector<T>a(n);
    vector<int>s;
    for (auto &[l, r]: a){
        cin >> l >> r;
        s.emplace_back(l);
        s.emplace_back(r);
    }
    sort(s.begin(), s.end());
    s.erase(unique(s.begin(), s.end()), s.end());
    auto get = [&](int x){ return (int)(lower_bound(s.begin(), s.end(), x)-s.begin());};
    for (auto &[l, r]: a){
        l = get(l); r = get(r);
        debug(l, r);
    }
    int m = (int)s.size();
   
    vector<vector<int>>L(m), R(m);
    for (int i = 0; i<n; i++){
        auto [l, r] = a[i];
        L[l].emplace_back(i);
        R[r].emplace_back(i);
    }
    set<T>secik; //r, i
    vector up(n+1, vector<int>(K));
    for (int rep = 0; rep<m; rep++){
        for (auto i: L[rep]){
            secik.insert({a[i].second, i});
        }
        for (auto i: R[rep]){
            secik.erase({rep, i});
            if (!secik.empty()) up[i][0] = secik.rbegin()->second;
            else up[i][0] = i;
            debug(i, up[i][0]);
            secik.insert({rep, i});
        }
        for (auto i: R[rep]){
            secik.erase({rep, i});
        }
    }
    for (int j = 1; j<K; j++){
        for (int i = 0; i<n;i++){
            up[i][j] = up[up[i][j-1]][j-1];
        }
    }
    while (q--){
        int l, r; cin >> l >> r;
        --l;--r;
        int ans = oo;
        int ll = 0, rr = n;
        while (rr >= ll){
            int mid = (ll+rr)/2;
            int curr = l;
            for (int i = K-1; i>=0; i--){
                // debug(i, l, up[l][i]);
                if (mid&(1<<i)){
                    curr = up[curr][i];
                }
            }
            if (a[curr].second > a[r].second){
                rr = mid-1;
            } else if (a[curr].second >= a[r].first){
                ans = mid;
                rr = mid-1;
            } else {
                ll = mid+1;
            }
        }
        if (ans == oo) {
            cout << "impossible\n";
            continue;
        }
        for (int i = K-1; i>=0; i--){
            if (ans&(1<<i)){
                l = up[l][i];
            }
        }
        debug(ans);
        if (a[l].second < a[r].first || a[l].second > a[r].second){
            cout << "impossible\n";
            continue;
        }
        if (l != r) ans++;
        cout << ans << "\n";
    }
}

int32_t main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int t = 1;
    //cin >> t;
    while (t--) solve();

    return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 199 ms 37624 KB Output is correct
3 Correct 306 ms 37768 KB Output is correct
4 Correct 333 ms 37648 KB Output is correct
5 Correct 280 ms 38336 KB Output is correct
6 Correct 255 ms 38604 KB Output is correct
7 Correct 237 ms 38912 KB Output is correct
8 Correct 181 ms 42884 KB Output is correct
9 Correct 197 ms 42884 KB Output is correct
10 Correct 368 ms 38204 KB Output is correct
11 Correct 325 ms 39948 KB Output is correct
12 Correct 117 ms 34336 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 2 ms 728 KB Output is correct
4 Correct 1 ms 604 KB Output is correct
5 Incorrect 1 ms 604 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 2 ms 728 KB Output is correct
4 Correct 1 ms 604 KB Output is correct
5 Incorrect 1 ms 604 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 2 ms 728 KB Output is correct
4 Correct 1 ms 604 KB Output is correct
5 Incorrect 1 ms 604 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 197 ms 37832 KB Output is correct
2 Correct 293 ms 37752 KB Output is correct
3 Correct 392 ms 37736 KB Output is correct
4 Correct 190 ms 42932 KB Output is correct
5 Correct 357 ms 38092 KB Output is correct
6 Correct 353 ms 42700 KB Output is correct
7 Correct 321 ms 42444 KB Output is correct
8 Correct 215 ms 42700 KB Output is correct
9 Correct 151 ms 46792 KB Output is correct
10 Correct 218 ms 42236 KB Output is correct
11 Correct 208 ms 43632 KB Output is correct
12 Correct 244 ms 42188 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 199 ms 37624 KB Output is correct
3 Correct 306 ms 37768 KB Output is correct
4 Correct 333 ms 37648 KB Output is correct
5 Correct 280 ms 38336 KB Output is correct
6 Correct 255 ms 38604 KB Output is correct
7 Correct 237 ms 38912 KB Output is correct
8 Correct 181 ms 42884 KB Output is correct
9 Correct 197 ms 42884 KB Output is correct
10 Correct 368 ms 38204 KB Output is correct
11 Correct 325 ms 39948 KB Output is correct
12 Correct 117 ms 34336 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 2 ms 728 KB Output is correct
16 Correct 1 ms 604 KB Output is correct
17 Incorrect 1 ms 604 KB Output isn't correct
18 Halted 0 ms 0 KB -