Submission #857447

#	Time	Username	Problem	Language	Result	Execution time	Memory
857447		Peti	Sum Zero (RMI20_sumzero)	C++17	100 / 100	201 ms	20176 KiB

sumzero

#include <bits/stdc++.h>
 
using namespace std;

const int maxn = 400005;
int v[maxn], nxt[maxn], jump[maxn], lvl[maxn];
 
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
 
    int n;
    cin>>n;
 
    v[0] = 0;
    for(int i = 1; i <= n; i++) cin>>v[i];
    long long sum = accumulate(v + 1, v + n + 1, 0LL);
    unordered_map<long long, int> mp;
    nxt[n+1] = n+1;
    int last = n+1;
    for(int i = n; i >= 0; i--){
        nxt[i] = mp.count(sum) ? mp[sum] : n+1;
        mp[sum] = i;
        sum -= v[i];
        if(nxt[i] < last){
            last = nxt[i];
        } else{
            nxt[i] = last;
        }
    }

    mp.clear();

    jump[n+1] = n+1;
    lvl[n+1] = 0;
    for(int i = n; i >= 0; i--){
        int x = nxt[i];
        if(lvl[x] == lvl[jump[x]]){
            lvl[i] = lvl[x]+1;
            jump[i] = jump[jump[x]];
        } else {
            lvl[i] = 1;
            jump[i] = nxt[i];
        }
    }
 
    int q;
    cin>>q;
    while(q--){
        int l, r;
        cin>>l>>r;
        --l;
        int ans = 0;
        while(nxt[l] <= r) {
            if(jump[l] <= r){
                ans += (1<<lvl[l]) - 1;
                l = jump[l];
            } else{
                ans++;
                l = nxt[l];
            }
        }
        cout << ans << '\n';
    }
 
    return 0;
}

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