Submission #1192806

#	Time	Username	Problem	Language	Result	Execution time	Memory
1192806		stefanopulos	Bigger segments (IZhO19_segments)	C++20	100 / 100	116 ms	22356 KiB

segments

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <bits/stdc++.h>
 
using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ldb;
 
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<ldb,ldb> pdd;

#define ff(i,a,b) for(int i = a; i <= b; i++)
#define fb(i,b,a) for(int i = b; i >= a; i--)
#define trav(a,x) for(auto& a : x)
 
#define sz(a) (int)(a).size()
#define fi first
#define se second
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

// os.order_of_key(k) the number of elements in the os less than k
// *os.find_by_order(k)  print the k-th smallest number in os(0-based)

const int mod = 1000000007;
const ll inf = (ll)1e18 + 5;
const int mxN = 500005; 

int n;
int niz[mxN];

ll pref[mxN];

ll dp[mxN][2];

ll bor[4 * mxN];
void build(int v, int tl, int tr){
    bor[v] = inf;
    if(tl == tr)return;
    int mid = (tl + tr) / 2;
    build(v * 2, tl, mid); build(v * 2 + 1, mid + 1, tr);
}
void update(int v, int tl, int tr, int pos, ll val){
    if(tl == tr){
        bor[v] = val;
        return;
    }
    int mid = (tl + tr) / 2;
    if(pos <= mid)update(v * 2, tl, mid, pos, val);
    else update(v * 2 + 1, mid + 1, tr, pos, val);
    bor[v] = min(bor[v * 2], bor[v * 2 + 1]);
}
int walk(int v, int tl, int tr, ll X){
    if(tl == tr)return tl;
    int mid = (tl + tr) / 2;
    if(bor[v * 2 + 1] <= X)return walk(v * 2 + 1, mid + 1, tr, X);
    else return walk(v * 2, tl, mid, X);
}

int main(){
    cin.tie(0)->sync_with_stdio(0);

    cin >> n;
    ff(i,1,n)cin >> niz[i];

    ff(i,1,n)pref[i] = pref[i - 1] + niz[i];

    build(1,0,n); update(1,0,n,0,0);
    ff(i,1,n){
        int j = walk(1,0,n,pref[i]);
        dp[i][0] = dp[j][0] + 1;
        dp[i][1] = pref[i] - pref[j];
        update(1,0,n,i,pref[i] + dp[i][1]);
    }

    cout << dp[n][0] << '\n';

    return 0;
}
/*

4
2 3 1 7

5
6 2 3 9 13

3
3 1 2

// probati bojenje sahovski
*/
 
 
 
 
 

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