Submission #537853

#	Time	Username	Problem	Language	Result	Execution time	Memory
537853		vladislav11	Sum Zero (RMI20_sumzero)	C++14	61 / 100	875 ms	65536 KiB

sumzero

#include <bits/stdc++.h>

using namespace std;

using ll = long long;

int n;
vector<ll> a;
vector<ll> nxt;
vector< vector<int> > jmp;

int main ()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    cin >> n;

    a.assign( n+1, 0 );
    for ( int i=1; i<=n; i++ )
        cin >> a[i];

    for ( int i=1; i<=n; i++ )
        a[i] += a[i-1];

    nxt.assign( n+1, -1 );

    map<ll,int> seen;

    for ( int i=n; i>=0; i-- )
    {
        if ( seen.count(a[i]) )
            nxt[i+1] = seen[ a[i] ];

        seen[ a[i] ] = i;
    }

    for ( int i=n-1; i>=0; i-- )
    {
        if ( nxt[i] == -1 )
            nxt[i] = nxt[i+1];
        else if ( nxt[i+1] != -1 )
            nxt[i] = min( nxt[i], nxt[i+1] );
    }

    /*for ( int i=0; i<=n; i++ )
            cout << a[i] << ' ';
    cout << '\n';

    for ( int i=0; i<=n; i++ )
        cout << nxt[i] << ' ';
    cout << '\n';*/

    jmp.assign( n+1, vector<int>( 21, n+1 ) );

    for ( int i=0; i<=n; i++ )
        jmp[i][0] = nxt[i]==-1 ? n+1 : nxt[i];

    for ( int p=1; p<21; p++ )
    for ( int i=0; i<=n; i++ )
    if ( jmp[i][p-1]+1 <= n )
        jmp[i][p] = jmp[ jmp[i][p-1]+1 ][p-1];

    /*for ( int i=0; i<=n; i++ )
    {
        cout << i << ": ";
        for ( int p=0; p<3; p++ )
            cout << jmp[i][p] << ' ';
        cout << '\n';
    }*/

    int q;
    cin >> q;
    while ( q-- )
    {
        int l, r;
        cin >> l >> r;

        int ans = 0;

        for ( int p=20; p>=0 && l <= r; p-- )
        {
            if ( jmp[l][p] <= r )
            {
                ans += 1<<p;
                l = jmp[l][p]+1;
            }

            //cout << p << " - " << l << '\n';
        }

        cout << ans << '\n';
    }

    return 0;
}

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