Submission #829553

#	Time	Username	Problem	Language	Result	Execution time	Memory
829553		GrindMachine	Sum Zero (RMI20_sumzero)	C++17	61 / 100	354 ms	47216 KiB

sumzero

// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*



*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

void solve(int test_case)
{
    int n; cin >> n;
    vector<int> a(n+5);
    rep1(i,n) cin >> a[i];

    vector<ll> pref(n+5);
    rep1(i,n) pref[i] = pref[i-1]+a[i];

    map<ll,int> mp;
    vector<int> lx(n+5,-1);

    rep1(i,n){
        mp[pref[i-1]] = i-1;
        ll p = pref[i];
        if(mp.count(p)){
            lx[i] = mp[p]+1;
        }
    }

    vector<int> start(n+5,inf1);
    rep1(i,n){
        if(lx[i] != -1){
            amin(start[lx[i]],i);
        }
    }
    rev(i,n,1) amin(start[i],start[i+1]);

    int LOG = 17;
    int up[n+5][LOG];
    rep(j,LOG) up[n+1][j] = n+1;
    rep1(i,n) up[i][0] = n+1;

    rep1(i,n){
        if(lx[i] == -1) conts;
        if(start[i+1] <= n){
            up[i][0] = start[i+1];
        }
    }

    rep1(j,LOG-1){
        rep1(i,n){
            up[i][j] = up[up[i][j-1]][j-1];
        }
    }

    int q; cin >> q;
    
    while(q--){
        int l,r; cin >> l >> r;
        int s = start[l];
        int ans = 0;

        if(s <= r){
            int u = s;
            ans = 1;

            rev(j,LOG-1,0){
                if(up[u][j] <= r){
                    u = up[u][j];
                    ans += 1<<j;
                }
            }
        }

        cout << ans << endl;
    }
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

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