제출 #1355306

#제출 시각아이디문제언어결과실행 시간메모리
1355306JohanSum Zero (RMI20_sumzero)C++20
22 / 100
175 ms27360 KiB
#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9 + 4;
const int N = 4e5 + 5;
const int LG = 19;
int a[N], c[N], st[N][LG], lg[N], up[N][LG], dpt[N];
long long pr[N];
vector < int > adj[N];
void build(int n){
  lg[1] = 0;
  for(int i = 2; i <= n; i++)
    lg[i] = lg[i / 2] + 1;
  for(int i = 1; i <= n; i++)
    st[i][0] = c[i];
  for(int j = 1; (1 << j) <= n; j++){
    for(int i = 1; i + (1 << j) - 1 <= n; i++){
      st[i][j] = max(st[i][j - 1], st[i + (1 << (j - 1))][j - 1]);
    }
  }
}
int ask(int l, int r){
  int j = lg[r - l + 1];
  return max(st[l][j], st[r - (1 << j) + 1][j]);
}
void dfs(int u, int p){
  dpt[u] = dpt[p] + 1;
  up[u][0] = p;
  for(int i = 1; i < LG; i++)
    up[u][i] = up[up[u][i - 1]][i - 1];
  for(auto v : adj[u]){
    if(v == p)
      continue;
    dfs(v, u);
  }
}
int get_up(int u, int k){
  k--;
  if(dpt[u] <= k)
    return INF;
  for(int i = 0; i < LG; i++){
    if((1ll << i) & k)
      u = up[u][i];
  }
  return u;
}
signed main(){
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n;
  cin >> n;
  map < long long , int > mp;
  mp[0] = 0;
  for(int i = 1; i <= n; i++){
    cin >> a[i];
    pr[i] = pr[i - 1] + a[i];
    c[i] = mp.count(pr[i]) == 0 ? -1 : mp[pr[i]] + 1;
    mp[pr[i]] = i;
  }
  build(n);
  for(int i = 1; i <= n; i++){
    int l = i, r = n;
    int best = n + 1;
    while(r >= l){
      int mid = (l + r) >> 1;
      if(ask(i, mid) > i){
        best = mid;
        r = mid - 1;
      }
      else l = mid + 1;
    }
    adj[best].push_back(i);
    adj[i].push_back(best);
  }
  dfs(n + 1, n + 1);
  int q;
  cin >> q;
  while(q--){
    int l, r;
    cin >> l >> r;
    int lst = -1, sz = 0, i = 0;
    int lo = 1, hi = r;
    while(hi >= lo){
      int mid = (lo + hi) >> 1;
      if(ask(1, mid) < l){
        i = mid;
        lo = mid + 1;
      }
      else hi = mid - 1;
    }
    i++;
    lo = 0, hi = INF;
    sz = (i <= r);
    while(lo <= hi){
      int mid = (lo + hi) >> 1;
      if(get_up(i, mid) <= r){
        sz = mid;
        lo = mid + 1;
      }
      else hi = mid - 1;
    }
    cout << sz << "\n";
  }
}
/*
3 2 2 2 4
3 3 3 2 4

*/
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