Submission #1122875

#	Time	Username	Problem	Language	Result	Execution time	Memory
1122875		Ice_man	Bigger segments (IZhO19_segments)	C++17	0 / 100	0 ms	328 KiB

segments

/**
 ____    ____    ____    __________________    ____    ____    ____
||I ||  ||c ||  ||e ||  ||                ||  ||M ||  ||a ||  ||n ||
||__||  ||__||  ||__||  ||________________||  ||__||  ||__||  ||__||
|/__\|  |/__\|  |/__\|  |/________________\|  |/__\|  |/__\|  |/__\|

*/

#include <iostream>
#include <chrono>
#include <vector>
#include <algorithm>

#define maxn 100005
#define maxlog 20
#define INF 1000000010
#define LINF 1000000000000000005
#define endl '\n'
#define pb(x) push_back(x)
#define X first
#define Y second
#define control cout<<"passed"<<endl;

using namespace std;


typedef pair <int, int> pii;
typedef long long ll;
typedef pair <ll, ll> pll;
typedef pair <int, ll> pil;
typedef pair <ll, int> pli;
typedef long double ld;



ll tree[maxn * 4];


void build(int node , int l , int r)
{
    if(l == r)
    {
        tree[node] = 1e18;
        return;
    }

    int mid = (l + r) / 2;

    build(node * 2 , l , mid);
    build(node * 2 + 1 , mid + 1 , r);

    tree[node] = min(tree[node * 2] , tree[node * 2 + 1]);
}

void update(int node , int l , int r , int qpos , int qval)
{
    if(l == r)
    {
        tree[node] = qval;
        return;
    }

    int mid = (l + r) / 2;

    if(qpos <= mid)
        update(node * 2 , l , mid , qpos , qval);
    else
        update(node * 2 + 1 , mid + 1 , r , qpos , qval);
    tree[node] = min(tree[node * 2] , tree[node * 2 + 1]);
}

ll query(int node , int l , int r , int ql , int qr)
{
    if(l > qr || r < ql)
        return 1e18;
    if(l >= ql && r <= qr)
        return tree[node];

    int mid = (l + r) / 2;

    return min(query(node * 2 , l , mid , ql , qr) ,
                query(node * 2 + 1 , mid + 1 , r , ql , qr));
}




int n;
int a[maxn];
pll dp[maxn];
ll pref[maxn];
ll minn[maxn];

void read()
{
    cin >> n;

    for(int i = 1; i <= n; i++)
        cin >> a[i];
    dp[1] = {1, a[1]};
    build(1 , 1 , n);

    update(1 , 1 , n , 1 , a[1] + a[1]);

    pref[0] = 0;
    for(int i = 1; i <= n; i++)
        pref[i] = pref[i - 1] + a[i];

    for(int i = 2; i <= n; i++)
    {
        dp[i] = {dp[i - 1].X, dp[i - 1].Y + a[i]};
        int l = 1, r = n - 1;
        int pos = -1;

        while(l <= r)
        {
            int mid = (l + r) / 2;

            if(query(1 , 1 , n , 1 , mid) <= pref[i])
                l = mid + 1, pos = mid;
            else
                r = mid - 1;
        }
        
        if(pos == -1)
            dp[i] = {dp[i - 1].X, dp[i - 1].Y + a[i]};
        else
            dp[i] = {dp[pos].X + 1, pref[i] - pref[pos]};
        update(1 , 1 , n , i , dp[i].Y + pref[i]);
    }


    //for(int i = 1; i <= n; i++)
    //  cout << dp[i].X << " " << dp[i].Y << endl;


    cout << dp[n].X << endl;
}











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

    read();


    return 0;
}

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