Submission #1147772

#	Time	Username	Problem	Language	Result	Execution time	Memory
1147772		vicvic	Fountain (eJOI20_fountain)	C++20	100 / 100	242 ms	35832 KiB

fountain

#include <iostream>
#include <algorithm>
#include <stack>
#include <cstdint>
#define int long long
using namespace std;
int n, q;
struct reservoir
{
    int d, c;
} v[100005];
int dr[100005], stiva[100005], cnt;
pair <int, int> table[100005][20];
void solve ()
{
    int ptr, val;
    cin >> ptr >> val;
    for (int bit=17;bit>=0;bit--)
    {
        if (table[ptr][bit].second<val)
        {
            val-=table[ptr][bit].second;
            ptr=table[ptr][bit].first;
        }
    }
    cout << (ptr==n+1?0:ptr) << "\n";
}
int32_t main ()
{
    ios :: sync_with_stdio (0);
    cin.tie (nullptr);
    cin >> n >> q;
    for (int i=1;i<=n;i++)
    {
        cin >> v[i].d >> v[i].c;
    }
    v[n+1].d=1e9+1;
    v[n+1].c=0;
    stiva[++cnt]=n+1;
    for (int i=n;i>=1;i--)
    {
        while (cnt && v[stiva[cnt]].d<=v[i].d)
        {
            cnt--;
        }
        dr[i]=stiva[cnt];
        stiva[++cnt]=i;
    }
    dr[n+1]=n+1;
    for (int i=n+1;i>=1;i--)
    {
        table[i][0].first=dr[i];
        table[i][0].second=v[i].c;
        for (int p=1;p<=17;p++)
        {
            table[i][p].first=table[table[i][p-1].first][p-1].first;
            table[i][p].second=table[i][p-1].second+table[table[i][p-1].first][p-1].second;
        }
    }
    while (q--)
    {
        solve ();
    }
    return 0;
}

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