Submission #1006224

#	Time	Username	Problem	Language	Result	Execution time	Memory
1006224		andecaandeci	Bigger segments (IZhO19_segments)	C++17	100 / 100	56 ms	20620 KiB

segments

#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
typedef long long ll;
const ll INF = 1e18;
const ll MOD = 1e9 + 7;
const ll MAXN = 1e6 + 5;
const ll LOG = 31;
#define vll vector <ll>
#define pll pair <ll, ll>
#define fi first
#define se second
#define endl '\n'

ll n, m, d;
ll a [MAXN], pf [MAXN], pos [MAXN], dp [MAXN];

ll lb(ll x){
    ll l = 1, r = n, ret = n+1;
    while(l <= r){
        ll mid = (l+r)/2;
        if(pf[mid] >= x){
            ret = mid;
            r = mid - 1;
        }
        else{
            l = mid + 1;
        }
    }
    return ret;
}

void solve(){
    cin >> n;
    for(ll i = 1; i <= n; i++){
        cin >> a[i];
        pf[i] = pf[i-1] + a[i];
    }
    for(ll i = 1; i <= n; i++){
        pos[i] = max(pos[i], pos[i-1]);
        dp[i] = dp[pos[i]] + 1;
        pos[lb(2*pf[i]-pf[pos[i]])] = i;
    }
    cout << dp[n] << endl;
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    // ll t; cin >> t;
    // while(t--){
        solve();
    // }
}

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