Submission #1097367

#	Time	Username	Problem	Language	Result	Execution time	Memory
1097367		anhthi	Bigger segments (IZhO19_segments)	C++14	100 / 100	161 ms	34644 KiB

segments

#include <bits/stdc++.h>
 
using namespace std;
 
#define fi first
#define se second
#define ll long long
#define mp(x, y) make_pair(x, y)
#define sz(v) ((int) (v).size())
#define all(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define BIT(x, y) (((x) >> (y)) & 1)
#define pb push_back
#define max_rng *max_element
#define min_rng *min_element
#define rep(i, n) for(int i = 1, _n = (n); i <= _n; ++i)
#define forn(i, a, b) for(int i = (a), _b = (b); i <= _b; ++i)
#define ford(i, a, b) for(int i = (a), _b = (b); i >= _b; --i)
 
template <class X, class Y>
    inline bool maximize(X &x, Y y) {
        return (x < y ? x = y, true : false);
    }
 
template <class X, class Y>
    inline bool minimize(X &x, Y y) {
        return (x > y ? x = y, true : false);
    }
 
template <class X>
    inline void compress(vector<X> &a) {
        sort(all(a));
        a.resize(unique(all(a)) - a.begin());
    }
 
int ctz(ll x) { return __builtin_ctzll(x); }
int lg(ll x) { return 63 - __builtin_clzll(x); }
int popcount(ll x) { return __builtin_popcount(x); }
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) {
    return l + abs((ll) rng()) % (r - l + 1);
}
 
const ll oo = (ll) 1e17;
const int inf = (ll) 1e9 + 7, mod = (ll) 1e9 + 7;
 
const int N = 6e5 + 5, M = 2e5 + 5, BASE = 307, LOG = 23;
 
void add(int &x, int y) { x += y; if (x >= mod) x -= mod; }
void sub(int &x, int y) { x -= y; if (x < 0) x += mod; }

int n;
int a[N];

ll pf[N];
pair<ll, ll> f[N];

struct Seg {

    int n;
    vector<ll> st;

    Seg(int n) : n(n) {
        st.resize(n << 2);
    }

    void upd(int p, ll val) {
        int i = 1; 
        for (int l = 0, r = n; l < r; ) {
            int m = (l + r) >> 1;
            if (p > m) {
                l = m + 1;
                i = 2 * i + 1;
            }
            else {
                r = m;
                i = 2 * i;
            }
        }
        st[i] = val;
        while (i > 1) {
            i >>= 1;
            st[i] = min(st[2 * i], st[2 * i + 1]);
        }
    }
    int walk(int i, int l, int r, ll x) {
        if (st[i] > x) return -1;
        while (true) {
            if (l == r) return l;
            int m = (l + r) >> 1;
            if (st[2 * i + 1] <= x) {
                l = m + 1;
                i = 2 * i + 1;
            }
            else {
                r = m;
                i = 2 * i;
            }
        }
        return -1;
    }

    int findPos(int i, int l, int r, int u, int v, ll x) {
        if (l > v || r < u) return -1;
        if (l >= u && r <= v) return walk(i, l, r, x);
        int m = (l + r) >> 1;
        int pos = findPos(2 * i + 1, m + 1, r, u, v, x);
        if (pos != -1) return pos;
        return findPos(2 * i, l, m, u, v, x);
    }

    int findPos(int u, int v, ll x) {
        if (u > v) return 0;
        return findPos(1, 0, n, u, v, x);
    }


};

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

    cin >> n;
    rep(i, n) cin >> a[i];
    rep(i, n) pf[i] = pf[i - 1] + a[i];

    
    Seg s(n);
    s.upd(0, 0);
    forn(i, 1, n) {
        int pos = s.findPos(0, i - 1, pf[i]);
        f[i] = {f[pos].first + 1, pf[i] - pf[pos]};
        s.upd(i, f[i].second + pf[i]);
    }

    cout << f[n].first;

    return 0;
}

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