Submission #636456

#	Time	Username	Problem	Language	Result	Execution time	Memory
636456		danikoynov	Sum Zero (RMI20_sumzero)	C++14	61 / 100	91 ms	23068 KiB

sumzero

#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
typedef long long ll;
const int maxn = 4e5 + 10;

int n, q;
ll pref[maxn];
int sub[maxn], lvl[maxn], heavy[maxn], ch_head[maxn], par[maxn], ch_idx[maxn];
vector < int > g[maxn], ch;
void dfs(int v)
{
    heavy[v] = -1;
    sub[v] = 1;
    for (int u : g[v])
    {
        lvl[u] = lvl[v] + 1;
        par[u] = v;
        dfs(u);
        sub[v] += sub[u];
        if (heavy[v] == -1 || sub[u] > sub[heavy[v]])
            heavy[v] = u;
    }
}

void hld(int v, int tp)
{
    ch_idx[v] = ch.size();
    ch.push_back(v);
    ch_head[v] = tp;

    if (heavy[v] != -1)
    {
        hld(heavy[v], tp);
    }

    for (int u : g[v])
    {
        if (u == heavy[v])
            continue;
        hld(u, u);
    }
}
void solve()
{
    cin >> n;

    ll x;
    for (int i = 1; i <= n; i ++)
    {
        cin >> x;
        pref[i] = pref[i - 1] + x;
    }

    unordered_map < ll, int > last;
    int cl = n + 1;
    for (int i = n; i >= 0; i --)
    {
        if (last[pref[i]] != 0)
        cl = min(cl, last[pref[i]]);
        g[cl].push_back(i);
        last[pref[i]] = i;
    }
   if (n > 3e5)
        return;


   dfs(n + 1);
   hld(n + 1, n + 1);

    cin >> q;
   int l, r, v, lf, rf, mf;
   for (int i = 1; i <= q; i ++)
   {
       cin >> l >> r;
       v = l - 1;
       while(ch_head[v] <= r)
        v = par[ch_head[v]];
       rf = ch_idx[v], lf = ch_idx[ch_head[v]];
       while(lf <= rf)
       {
           mf = (lf + rf) / 2;
           if (ch[mf] > r)
            lf = mf + 1;
           else
            rf = mf - 1;
       }
       cout << lvl[l - 1] - lvl[ch[rf]] - 1 << endl;
   }
}

void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}
int main()
{
    speed();
    ///freopen("input.txt", "r", stdin);
    solve();
   return 0;
}
/**

*/

• Subtask 1: 22 / 22
• Subtask 2: 39 / 39
• Subtask 3: 0 / 39