oj.uz

Submission #468017

# Submission time Handle Problem Language Result Execution time Memory
468017 2021-08-25T21:39:12 Z jk_ Fountain (eJOI20_fountain) C++14
100 / 100
 509 ms 50196 KB 
#include <bits/stdc++.h>
#define int long long
 
using namespace std;
 
const int INF = 1e18;
 
vector<vector<pair<int, int>>> adj;
vector<vector<pair<int, int>>> par;
 
void dfs(int v) {
    //cerr << v << " -- v start\n";
    for (auto [u, ci] : adj[v]) {
        par[u][0] = {v, ci};
        dfs(u);
    }
    //cerr << v << " -- v end\n"; 
}
 
signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
 
    int n, q;
    cin >> n >> q;
 
    int log_n = __lg(n-1) + 1;
 
    //cerr << log_n;
 
    vector<pair<int, int>> resv; // di, ci
    for (int i=0; i<n; i++) {
        int di, ci;
        cin >> di >> ci;
        resv.push_back({di, ci});
    }
    resv.push_back({INF, INF}); // Add the waterway
    reverse(resv.begin(), resv.end());
 
    adj.assign(n+1, {});
 
    vector<int> st; 
    st.push_back(0);
    for (int i=1; i<=n; i++) {
        while (resv[st.back()].first <= resv[i].first) {
            //cerr << st.back() << "\n";
            st.pop_back();
        }
        adj[st.back()].push_back({i, resv[i].second});
        //adj[i].push_back({st.back(), resv[i].second});
        st.push_back(i);
    }
 
    //cerr << "run1\n";
 
    // Compute binary lift
    par.assign(n+1, vector<pair<int, int>>(log_n+1, {-1, INF}));
    dfs(0);
 
    //cerr << "run2\n";
 
    for (int k=1; k<=log_n; k++) {
        for (int i=1; i<=n; i++) {
            if (par[i][k-1].first < 0) { continue; }
            par[i][k] = {par[par[i][k-1].first][k-1].first, par[i][k-1].second + par[par[i][k-1].first][k-1].second};
            //cerr << par[i][k].first << " ";
        }
        //cerr << "\n";
    }
    
    //cerr << "run3\n";
 
    //return 0;
 
    for (int i=0; i<q; i++) {
        int ri, vi;
        cin >> ri >> vi;
 
        //cerr << "run0" << "\n";
        
        int lvl = n - ri + 1;
        int vol_sum = 0;
        while (vol_sum+par[lvl][0].second < vi) {
            //cerr << vol_sum+par[lvl][0].second << " -- dbg2\n";
            int pow = 1;
            while (pow-1 <= log_n && vol_sum+par[lvl][pow-1].second < vi) {
                pow++;
            }
            vol_sum += par[lvl][pow-2].second;
            lvl = par[lvl][pow-2].first;
            //cerr << vol_sum+par[lvl][0].second << " -- dbg\n";
        }
 
        //cerr << vol_sum << "\n";
        //cerr << "calc end\n";
 
        if (lvl == 0) {
            cout << 0 << "\n";
        } else {
            cout << n - lvl + 1 << "\n";
        }
    }
 
}

Compilation message

fountain.cpp: In function 'void dfs(long long int)':
fountain.cpp:13:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   13 |     for (auto [u, ci] : adj[v]) {
      |               ^

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 460 KB Output is correct
3 Correct 1 ms 460 KB Output is correct
4 Correct 1 ms 588 KB Output is correct
5 Correct 2 ms 588 KB Output is correct
6 Correct 2 ms 588 KB Output is correct
7 Correct 2 ms 640 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 333 ms 43728 KB Output is correct
2 Correct 353 ms 43248 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 460 KB Output is correct
3 Correct 1 ms 460 KB Output is correct
4 Correct 1 ms 588 KB Output is correct
5 Correct 2 ms 588 KB Output is correct
6 Correct 2 ms 588 KB Output is correct
7 Correct 2 ms 640 KB Output is correct
8 Correct 333 ms 43728 KB Output is correct
9 Correct 353 ms 43248 KB Output is correct
10 Correct 2 ms 588 KB Output is correct
11 Correct 122 ms 23756 KB Output is correct
12 Correct 509 ms 50196 KB Output is correct
13 Correct 320 ms 44740 KB Output is correct
14 Correct 196 ms 43008 KB Output is correct
15 Correct 177 ms 42412 KB Output is correct