Submission #604016

#	Time	Username	Problem	Language	Result	Execution time	Memory
604016		Ozy	Bigger segments (IZhO19_segments)	C++17	0 / 100	1 ms	340 KiB

segments

#include <iostream>
#include <bits/stdc++.h>
using namespace std;
#define lli long long int
#define rep(i,a,b) for (int i = (a); i <= (b);i++)
#define repa(i,a,b) for (int i = (a); i >= (b);i--)
#define debug(a) cout << #a << " = " << a << endl
#define debugsl(a) cout << #a << " = " << a << ", "

#define MAX 500000
#define val first
#define res second
#define INF 1000000000000

lli n,a,ub;
lli prim[MAX+2],ult[MAX+2],res[MAX+2],arr[MAX+2],acu[MAX+2],bi[MAX+2],bf[MAX+2];
pair<lli,lli> dp[MAX+2];

lli binaria(lli f, lli busco) {
    lli fin = bf[busco - 1];
    lli ini = bi[busco - 1];
    lli a,b,mitad,last = -1;

    while (ini <= fin) {
        mitad = (ini+fin)/2;

        a = dp[mitad].first;

        b = acu[f] - acu[mitad];

        if (a <= b) {
            last = mitad;
            ini = mitad+1;
        }
        else fin = mitad-1;
    }
    return last;
}

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

    cin >> n;
    rep(i,1,n) {
        cin >> arr[i];
        acu[i] = arr[i] + acu[i-1];
    }

    fill(prim, prim + 1 + n, n);
    dp[1] = {arr[1],INF};
    res[1] = 1;
    prim[1] = ult[1] = 1;
    bi[1] = bf[1] = 1;
    ub = 1;

    //ciudado con el second 0
    rep(i,2,n) {
        dp[i].first = dp[i - 1].first + arr[i];
        res[i] = res[i - 1];
        repa(g, ub + 1, 2){
            a = binaria(i, g);
            if (a != -1){
                res[i] = max(res[i], res[a] + 1);
                dp[i].first = min(dp[i].first, acu[i] - acu[a]);
                break;
            }
        }

        if (dp[i].first > dp[i - 1].first){
            ++ub;
            bi[ub] = i;
        }
        bf[ub] = i;
    }

    cout << res[n];
}

• Subtask 1: 0 / 13
• Subtask 2: 0 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27