Submission #1127197

#	Time	Username	Problem	Language	Result	Execution time	Memory
1127197		tfgs	Fountain (eJOI20_fountain)	C++17	100 / 100	275 ms	31560 KiB

fountain

#include <bits/stdc++.h>
using namespace std;
#define int int64_t
const int inf=1e18;

#ifdef LOCAL
#include "algo/debug.h"
#else
template <typename... Args>
void dummy(Args&&... args){}
#define ps dummy
#endif

#define f first
#define s second
template<class T> using V = vector<T>; 
using vi = V<int>;
using vb = V<bool>;
using vs = V<string>;

#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x) 
#define len(x) (int)((x).size())
#define rsz resize
#define ins insert
#define ft front()
#define bk back()
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define ai2 array<int,2>
#define ai3 array<int,3>
#define ai4 array<int,4>
#define ai5 array<int,5>
template<class T> int lwb(const V<T>& a, const T& b) { return lb(all(a),b)-begin(a); }
template<class T> int upb(const V<T>& a, const T& b) { return ub(all(a),b)-begin(a); }
template<class T> bool ckmin(T& a, const T& b) { return a > b ? a=b, true : false; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a=b, true : false; }
#define pct __builtin_popcount
#define ctz __builtin_ctz
#define clz __builtin_clz
constexpr int p2(int x) { return (int)1 << x; }
constexpr int bits(int x) { return x == 0 ? 0 : 31-clz(x); } // floor(log2(x)) 
template<class T>void UNIQUE(V<T>& v) { sort(all(v)); v.erase(unique(all(v)),end(v)); }
template<class T,class U>void erase(T& t, const U& u) { auto it = t.find(u); assert(it != end(t)); t.erase(it); }

const int LOG = 16;

void solve() {
    int n, q; cin >> n >> q;
    vi D(n), C(n);
    for (int i = 0; i < n; i++) {
        cin >> D[i] >> C[i];
    }

    vi stk;
    vector lift(LOG + 1, V<ai2>(n, { -1, 0 }));
    for (int i = 0; i < n; i++) {
        while (len(stk) && D[i] > D[stk.bk]) {
            lift[0][stk.bk] = { i, C[i] };
            stk.pop_back();
        }
        stk.pb(i);
    }

    for (int pw = 1; pw <= LOG; pw++) {
        for (int i = 0; i < n; i++) {
            auto [j, c] = lift[pw - 1][i];
            if (j == -1) {
                lift[pw][i] = lift[pw - 1][i];
            } else {
                lift[pw][i] = lift[pw - 1][j];
                lift[pw][i][1] += lift[pw - 1][i][1];
            }
        }
    }

    while (q--) {
        int i, water; cin >> i >> water; i--;
        water -= C[i];
        if (water <= 0) {
            cout << i + 1 << '\n';
            continue;
        }
        for (int pw = LOG; pw >= 0; pw--) {
            auto [j, c] = lift[pw][i];
            if (c < water && j != -1) {
                water -= c;
                i = j;
            }
        }
        int ans = lift[0][i][0] == -1 ? 0 : lift[0][i][0] + 1;
        cout << ans << '\n';
    }
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    solve();
    return 0;
}

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