Submission #1098271

#TimeUsernameProblemLanguageResultExecution timeMemory
1098271NeltSum Zero (RMI20_sumzero)C++17
22 / 100
927 ms22068 KiB
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define endl "\n"

using namespace std;
using namespace __gnu_pbds;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T, typename key = less<T>>
using ordered_set = tree<T, null_type, key, rb_tree_tag, tree_order_statistics_node_update>;
const ll lg = 20, N = 4e5 + 5;
ll up[lg][N];
void solve()
{
    ll n;
    cin >> n;
    ll a[n + 1], pref[n + 1];
    pref[0] = 0;
    for (ll i = 1; i <= n; i++)
        cin >> a[i], pref[i] = pref[i - 1] + a[i];
    map<ll, ll> last;
    ll mn = n + 1;
    for (ll i = n; i >= 1; i--)
    {
        last[pref[i]] = i;
        if (last.count(pref[i - 1])) mn = min(mn, last[pref[i - 1]]);
        up[0][i] = mn + 1;
    }
    // for (ll i = 1; i <= n; i++) cout << up[0][i] << " \n"[i == n];
    for (ll i = 0; i < lg; i++) up[i][n + 1] = n + 2;
    for (ll bit = 1; bit < lg; bit++)
    for (ll i = 1; i <= n; i++) up[bit][i] = min(n + 2, up[bit - 1][up[bit - 1][i]]);
    ll q;
    cin >> q;
    while (q--)
    {
        ll l, r;
        cin >> l >> r;
        ll ans = 0;
        // for (ll bit = lg - 1; bit >= 0; bit--)
        //     if (up[bit][l] <= r + 1) ans += 1 << bit, l = up[bit][l];
        while (up[0][l] <= r + 1) ans++, l = up[0][l];
        cout << ans << endl;
    }
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll t = 1;
    // precomp();
    // cin >> t;
    for (ll cs = 1; cs <= t; cs++)
        solve();
    // cerr << "\nTime elapsed: " << clock() * 1000.0 / CLOCKS_PER_SEC << " ms\n";
}
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