Submission #748883

# Submission time Handle Problem Language Result Execution time Memory
748883 2023-05-27T06:22:42 Z GrindMachine Event Hopping (BOI22_events) C++17
25 / 100
1500 ms 6572 KB
// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*



*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

template<typename T>
struct segtree {
    // https://codeforces.com/blog/entry/18051

    /*=======================================================*/

    struct data {
        int a;
    };

    data neutral = {inf1};

    data merge(data &left, data &right) {
        data curr;
        curr.a = min(left.a,right.a);
        return curr;        
    }

    void create(int i, T v) {
        tr[i].a = v;
    }

    void modify(int i, T v) {
        amin(tr[i].a, v);
    }

    /*=======================================================*/

    int n;
    vector<data> tr;

    segtree() {

    }

    segtree(int siz) {
        init(siz);
    }

    void init(int siz) {
        n = siz;
        tr.assign(2 * n, neutral);
    }

    void build(vector<T> &a, int siz) {
        rep(i, siz) create(i + n, a[i]);
        rev(i, n - 1, 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
    }

    void pupd(int i, T v) {
        modify(i + n, v);
        for (i = (i + n) >> 1; i; i >>= 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
    }

    data query(int l, int r) {
        data resl = neutral, resr = neutral;

        for (l += n, r += n; l <= r; l >>= 1, r >>= 1) {
            if (l & 1) resl = merge(resl, tr[l++]);
            if (!(r & 1)) resr = merge(tr[r--], resr);
        }

        return merge(resl, resr);
    }
};

void solve(int test_case)
{
    int n,q; cin >> n >> q;
    vector<pii> a(n+5);
    rep1(i,n) cin >> a[i].ff >> a[i].ss;

    vector<int> b;
    rep1(i,n) b.pb(a[i].ff), b.pb(a[i].ss);

    sort(all(b));
    b.resize(unique(all(b))-b.begin());
    int siz = sz(b);

    rep1(i,n){
        a[i].ff = lower_bound(all(b),a[i].ff) - b.begin();
        a[i].ss = lower_bound(all(b),a[i].ss) - b.begin();
    }

    vector<pii> order;
    rep1(i,n) order.pb({a[i].ss, i});
    sort(all(order));

    while(q--){
        int u,v; cin >> u >> v;
        if(u == v){
            cout << 0 << endl;
            conts;
        }
    
        vector<int> dp(n+5,inf1);
        dp[u] = 0;
        segtree<int> st(siz+5);
        st.pupd(a[u].ss, 0);

        for(auto [val, i] : order){
            if(i == u or i == v) conts;
            int best = st.query(a[i].ff, a[i].ss).a;
            dp[i] = best + 1;
            st.pupd(a[i].ss, dp[i]);
        }

        {
            int i = v;
            int best = st.query(a[i].ff, a[i].ss).a;
            dp[i] = best + 1;
            st.pupd(a[i].ss, dp[i]);
        }

        int ans = dp[v];

        if(ans <= n){
            cout << ans << endl;
        }
        else{
            cout << "impossible" << endl;
        }
    }
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}
# Verdict Execution time Memory Grader output
1 Correct 0 ms 336 KB Output is correct
2 Execution timed out 1584 ms 3812 KB Time limit exceeded
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 4 ms 340 KB Output is correct
4 Correct 5 ms 340 KB Output is correct
5 Correct 4 ms 360 KB Output is correct
6 Correct 4 ms 340 KB Output is correct
7 Correct 9 ms 340 KB Output is correct
8 Correct 7 ms 372 KB Output is correct
9 Correct 2 ms 340 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 4 ms 340 KB Output is correct
4 Correct 5 ms 340 KB Output is correct
5 Correct 4 ms 360 KB Output is correct
6 Correct 4 ms 340 KB Output is correct
7 Correct 9 ms 340 KB Output is correct
8 Correct 7 ms 372 KB Output is correct
9 Correct 2 ms 340 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 4 ms 340 KB Output is correct
13 Correct 4 ms 340 KB Output is correct
14 Correct 4 ms 340 KB Output is correct
15 Correct 5 ms 340 KB Output is correct
16 Correct 9 ms 340 KB Output is correct
17 Correct 9 ms 340 KB Output is correct
18 Correct 2 ms 340 KB Output is correct
19 Execution timed out 1592 ms 572 KB Time limit exceeded
20 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 4 ms 340 KB Output is correct
4 Correct 5 ms 340 KB Output is correct
5 Correct 4 ms 360 KB Output is correct
6 Correct 4 ms 340 KB Output is correct
7 Correct 9 ms 340 KB Output is correct
8 Correct 7 ms 372 KB Output is correct
9 Correct 2 ms 340 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 4 ms 340 KB Output is correct
13 Correct 4 ms 340 KB Output is correct
14 Correct 4 ms 340 KB Output is correct
15 Correct 5 ms 340 KB Output is correct
16 Correct 9 ms 340 KB Output is correct
17 Correct 7 ms 340 KB Output is correct
18 Correct 2 ms 340 KB Output is correct
19 Correct 561 ms 3856 KB Output is correct
20 Correct 588 ms 5008 KB Output is correct
21 Correct 874 ms 5812 KB Output is correct
22 Correct 644 ms 6160 KB Output is correct
23 Correct 1166 ms 6572 KB Output is correct
24 Correct 846 ms 6572 KB Output is correct
25 Correct 166 ms 4668 KB Output is correct
# Verdict Execution time Memory Grader output
1 Execution timed out 1584 ms 3804 KB Time limit exceeded
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 0 ms 336 KB Output is correct
2 Execution timed out 1584 ms 3812 KB Time limit exceeded
3 Halted 0 ms 0 KB -