oj.uz

Submission #802995

# Submission time Handle Problem Language Result Execution time Memory
802995 2023-08-02T17:35:48 Z andreiomd Fountain (eJOI20_fountain) C++11
100 / 100
 191 ms 16308 KB 
#include <iostream>
#include <stack>

using namespace std;
using PII = pair<int, int>;

static constexpr int NMAX = (int)(1e5 + 1), LOGMAX = 17;

int Log2[NMAX];

int N, Q;
int D[NMAX], C[NMAX];

PII Next[LOGMAX][NMAX];

static inline void Read()
{
    ios_base ::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> N >> Q;
    for (int i = 1; i <= N; ++i)
        cin >> D[i] >> C[i], Next[0][i] = {0, 0};

    for (int i = 2; i <= N; ++i)
        Log2[i] = 1 + Log2[(i >> 1)];

    return;
}

static inline void Get_level_0()
{
    stack<int> S;

    for (int i = 1; i <= N; ++i)
    {
        while (!S.empty() && D[i] > D[S.top()])
            Next[0][S.top()].first = i, Next[0][S.top()].second += C[i], S.pop();

        S.push(i);
    }

    return;
}

static inline void Precompute()
{
    for (int i = 1; (1 << i) <= N; ++i)
        for (int j = 1; j <= N; ++j)
            Next[i][j] = {Next[i - 1][Next[i - 1][j].first].first, Next[i - 1][j].second + Next[i - 1][Next[i - 1][j].first].second};

    return;
}

static inline void Test_Case()
{
    int node = 0, target = 0;
    cin >> node >> target;

    if (C[node] >= target)
    {
        cout << node << '\n';
        return;
    }

    if (!Next[0][node].first)
    {
        cout << 0 << '\n';
        return;
    }

    target -= C[node];

    for (int i = Log2[N - node + 1]; i >= 0; --i)
        if (Next[i][node].first)
            if (target - Next[i][node].second >= 0)
                target -= Next[i][node].second, node = Next[i][node].first;

    if (target == 0)
        cout << node;
    else
        cout << Next[0][node].first;

    cout << '\n';

    return;
}

static inline void Solve()
{
    for (int q = 1; q <= Q; ++q)
        Test_Case();

    return;
}

int main()
{
    Read();

    Get_level_0();

    Precompute();

    Solve();

    return 0;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 1 ms 468 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 111 ms 14840 KB Output is correct
2 Correct 131 ms 13876 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 1 ms 468 KB Output is correct
8 Correct 111 ms 14840 KB Output is correct
9 Correct 131 ms 13876 KB Output is correct
10 Correct 1 ms 412 KB Output is correct
11 Correct 46 ms 8476 KB Output is correct
12 Correct 191 ms 15928 KB Output is correct
13 Correct 143 ms 15972 KB Output is correct
14 Correct 83 ms 15948 KB Output is correct
15 Correct 70 ms 16308 KB Output is correct