Submission #441457

#	Time	Username	Problem	Language	Result	Execution time	Memory
441457		elazarkoren	Fountain (eJOI20_fountain)	C++17	100 / 100	845 ms	34616 KiB

fountain

#include <iostream>
#include <vector>
#include <algorithm>
#include <stack>
#define x first
#define y second
#define int long long
using namespace std;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
typedef vector<pii> vii;

const int MAX_N = 1e5 + 2;
const int infinity = 1e9 + 1;

int d[MAX_N], c[MAX_N], loga[MAX_N];

int32_t main() {
    int n, q;
    cin >> n >> q;
    for (int i = 1; i <= n; i++) cin >> d[i] >> c[i];
    for (int i = 2; i <= n; i++) {
        loga[i] = loga[i >> 1] + 1;
    }
    vector<vii> dp(loga[n] + 1, vii(n + 2, {n + 1, infinity}));
    d[n + 1] = c[n + 1] = infinity;
    stack<int> stk;
    stk.push(n + 1);
    for (int i = n; i; i--) {
        while (d[stk.top()] <= d[i]) stk.pop();
        dp[0][i] = {stk.top(), c[i]};
        stk.push(i);
    }
    for (int i = 1; i <= loga[n]; i++) {
        for (int j = 1; j <= n; j++) {
            dp[i][j].x = dp[i - 1][dp[i - 1][j].x].x;
            dp[i][j].y = dp[i - 1][j].y + dp[i - 1][dp[i - 1][j].x].y;
        }
    }
    while (q--) {
        int r, v;
        cin >> r >> v;
        for (int i = loga[n]; i >= 0; i--) {
            if (dp[i][r].y < v) {
                v -= dp[i][r].y;
                r = dp[i][r].x;
            }
        }
        cout << (r == n + 1 ? 0 : r) << '\n';
    }
}

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