oj.uz

Submission #1025844

# Submission time Handle Problem Language Result Execution time Memory
1025844 2024-07-17T10:44:56 Z kkkkkkkk Fountain (eJOI20_fountain) C++14
100 / 100
 115 ms 39244 KB 
#include <bits/stdc++.h>

using namespace std;

vector<int> G[100005];
int n, q;
int dijametar[100005], kapacitet[100005];
int parent[100005][30], sobira[100005][30];

void dfs(int teme, int preth) {
    parent[teme][0]=preth;
    sobira[teme][0]=kapacitet[preth];
    for (auto next:G[teme]) {
        if (next!=preth)
            dfs(next, teme);
    }
}

void precomputeSparseMatrix() {
    for (int i=1;i<20;i++) {
        for (int teme=1;teme<=n+1;teme++) {
            if (parent[teme][i-1]!=-1) {
                parent[teme][i]=parent[parent[teme][i-1]][i-1];
                sobira[teme][i]=sobira[parent[teme][i-1]][i-1]+sobira[teme][i-1];
            }
        }
    }
}

int binary_lifting(int rezervoar, int voda) {
    voda-=kapacitet[rezervoar];
    for (int i=20;i>=0;i--) {
        if (parent[rezervoar][i]==-1) continue;
        if (sobira[rezervoar][i]<voda) {
            voda-=sobira[rezervoar][i];
            rezervoar=parent[rezervoar][i];
        }
    }
    return parent[rezervoar][0];
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cin >> n >> q;
    for (int i=1;i<=n;i++)
        cin >> dijametar[i] >> kapacitet[i];
    kapacitet[n+1]=2000000000;
    stack<pair<int,int> > s;
    s.push({INT_MAX, n+1});
    for (int i=n;i>=1;i--) {
        while (s.top().first<=dijametar[i])
            s.pop();
        G[i].push_back(s.top().second);
        G[s.top().second].push_back(i);
        s.push({dijametar[i], i});
    }
    memset(parent, -1, sizeof(parent));
    dfs(n+1, 0);
    precomputeSparseMatrix();
    while (q--) {
        int r, v;
        cin >> r >> v;
        if (kapacitet[r]>=v) cout << r << '\n';
        else {
            int rez=binary_lifting(r, v);
            if (rez==n+1) cout << 0 << '\n';
            else cout << rez << '\n';
        }
    }

    return 0;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 16472 KB Output is correct
2 Correct 4 ms 16476 KB Output is correct
3 Correct 3 ms 16732 KB Output is correct
4 Correct 3 ms 16732 KB Output is correct
5 Correct 4 ms 16732 KB Output is correct
6 Correct 3 ms 16732 KB Output is correct
7 Correct 4 ms 16732 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 77 ms 34384 KB Output is correct
2 Correct 81 ms 33876 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 16472 KB Output is correct
2 Correct 4 ms 16476 KB Output is correct
3 Correct 3 ms 16732 KB Output is correct
4 Correct 3 ms 16732 KB Output is correct
5 Correct 4 ms 16732 KB Output is correct
6 Correct 3 ms 16732 KB Output is correct
7 Correct 4 ms 16732 KB Output is correct
8 Correct 77 ms 34384 KB Output is correct
9 Correct 81 ms 33876 KB Output is correct
10 Correct 3 ms 16732 KB Output is correct
11 Correct 56 ms 29364 KB Output is correct
12 Correct 115 ms 39244 KB Output is correct
13 Correct 101 ms 35532 KB Output is correct
14 Correct 68 ms 34128 KB Output is correct
15 Correct 67 ms 35024 KB Output is correct