Submission #924243

#	Time	Username	Problem	Language	Result	Execution time	Memory
924243		raysh07	Pilot (NOI19_pilot)	C++17	89 / 100	1076 ms	127336 KiB

pilot

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define INF (int)1e18
#define f first
#define s second
const int N=2e5+69;
int ans=0;
mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());


class DisjointSets {
  private:
    vector<int> parents;
    vector<int> sizes;

  public:
    DisjointSets(int size) : parents(size), sizes(size, 1) {
        for (int i = 0; i < size; i++) { parents[i] = i; }
    }

    /** @return the "representative" node in x's component */
    int find(int x) {
        return parents[x] == x ? x : (parents[x] = find(parents[x]));
    }

    /** @return whether the merge changed connectivity */
    bool unite(int x, int y) {
        int x_root = find(x);
        int y_root = find(y);
        if (x_root == y_root) 
            { return false;
            }

        ans+=sizes[x_root]*sizes[y_root];
        if (sizes[x_root] < sizes[y_root]) { swap(x_root, y_root); }
        sizes[x_root] += sizes[y_root];
        parents[y_root] = x_root;
        return true;
    }

    /** @return whether x and y are in the same connected component */
    bool connected(int x, int y) { return find(x) == find(y); }
};

void Solve(){
    int n,q;
    cin>>n>>q;
    int H[n];
    int A[q];
    map <int,int> mp;
    for(int i=0;i<n;i++)
        cin>>H[i];
    
    for(int i=0;i<q;i++)
        cin>>A[i];

    vector <pair<int,int>> vec;
    
    for(int i=0;i<n;i++)
        vec.push_back({H[i],i});
        
    DisjointSets ds(n);
    
    sort(vec.begin(),vec.end());
    set <int> st;
    int cnt = 0;
    for(auto [x,i]: vec){
        if(i!=0&&H[i-1]<=H[i]){
            ds.unite(i-1,i); 
        }
        if(i!=n-1 && H[i+1]<=H[i])
            ds.unite(i,i+1); 
        cnt++;
        mp[x]=ans + cnt; 
        st.insert(x);
    }
    
    for(int i=0;i<q;i++){
        // we need to find the largest number <= x 
        auto it = st.upper_bound(A[i]);
        // this finds the first place with a number > x 
        // --it 
        if (it == st.begin()){
            cout << 0 << "\n";
        } else {
            --it;
            cout << mp[*it] << "\n";
        }
    }
}
int32_t main() 
{
    auto begin = std::chrono::high_resolution_clock::now();
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
    // freopen("in",  "r", stdin);
    // freopen("out", "w", stdout);
    
    //cin >> t;
    for(int i = 1; i <= t; i++) 
    {
        //cout << "Case #" << i << ": ";
        Solve();
    }
    auto end = std::chrono::high_resolution_clock::now();
    auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
    cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n"; 
    return 0;
}

• Subtask 1: 3 / 3
• Subtask 2: 10 / 10
• Subtask 3: 12 / 12
• Subtask 4: 15 / 15
• Subtask 5: 5 / 5
• Subtask 6: 9 / 9
• Subtask 7: 14 / 14
• Subtask 8: 10 / 10
• Subtask 9: 11 / 11
• Subtask 10: 0 / 11