Submission #1258091

#	Time	Username	Problem	Language	Result	Execution time	Memory
1258091		E_rK	Fountain (eJOI20_fountain)	C++20	100 / 100	287 ms	56320 KiB

fountain

#include <bits/stdc++.h>
#define fast cin.tie(0);cout.tie(0);ios_base::sync_with_stdio(false)
#define pb push_back
#define ppb pop_back
#define fi first
#define se second
#define sp " "
#define endl "\n"
#define mod 1000000007
#define MAXN 500005
#define MAXM 1000006
#define inf 1e18
#define INF 0x3f
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define debug(x) for(auto& a: x) cout << a << " "
 
using namespace std;
typedef long long int lo;
 
lo n,m,q,k,a,b;

lo arr[MAXN],dia[MAXN],vis[MAXN];
vector<lo> v[MAXN];
lo binlift[MAXN][33];
lo sub[MAXN];
void dfs(lo node, lo ata){
    // cout << node << sp << ata << sp << dia[node] << endl;
    if(node == n+1)
        return;
    if(vis[node])
        return;
    vis[node] = 1;
    sub[node] = arr[node];  
    for(auto go: v[node]){
        if(go != ata)
            dfs(go,node);
        sub[node] += sub[go];
        binlift[node][0] = go;
        for (int i = 1; i < 32; ++i)
        {
            binlift[node][i] = binlift[binlift[node][i-1]][i-1];
        }
    }
}
void solve(){
    cin >> n >> q;
    for (int i = 1; i <= n; ++i)
    {
        cin >> dia[i] >> arr[i];
    }
    vector<pair<lo,lo>> vec;
    vec.pb({dia[n],n});
    v[n].pb(n+1);
    for (int i = n-1; i > 0; i--)
    {
        while(vec.size() and vec.back().fi <= dia[i]){
            vec.pop_back();
        }
        if(vec.size() == 0){
            v[i].pb(n+1);
            vec.pb({dia[i],i});
        }
        else{
            v[i].pb(vec.back().se);
            vec.pb({dia[i],i});
        }
    }
    for (int i = 1; i <= n; ++i)
    {
        if(!vis[i])
            dfs(i,0);
        // cout << endl;
    }
    // for (int i = 1; i <= n; ++i)
    // {
    //     cout<<"sub: " << i << sp << sub[i] << endl;
    // }
    // for (int i = 1; i < n; ++i)
    // {
    //     cout << i << ": ";
    //     for (int j = 0; j < 3; ++j)
    //     {
    //         cout << binlift[i][j] << sp;
    //     }
    //     cout << endl;
    // }
    while(q--){
        lo a,b;
        cin >> a >> b;
        if(sub[a] < b){
            cout << 0 << endl;
            continue;
        }
        lo kalan = sub[a] - b;
        for (int i = 32; i >= 0; i--)
        {
            if(sub[binlift[a][i]] > kalan){
                a = binlift[a][i];
            }
        }
        cout << a << endl;
    }
}
int main()
{
    // cout << fixed << setprecision(12);
    // freopen("feast.in","r",stdin);
    // freopen("feast.out","w",stdout);
    fast;
    int t = 1;
    // cin >> t;
    while(t--)
    {
        solve();
    }
}

• Subtask 1: 30 / 30
• Subtask 2: 30 / 30
• Subtask 3: 40 / 40