Submission #771031

#	Time	Username	Problem	Language	Result	Execution time	Memory
771031		dxz05	Rabbit Carrot (LMIO19_triusis)	C++17	0 / 100	1 ms	212 KiB

triusis

#pragma GCC optimize("Ofast,O3,unroll-loops")
#pragma GCC target("avx,avx2")

#include <bits/stdc++.h>

using namespace std;

#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define bpc(x) __builtin_popcount(x)
#define bpcll(x) __builtin_popcountll(x)
#define MP make_pair
//#define endl '\n'

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

typedef long long ll;
const int MOD = 1e9 + 7;
const int N = 2e5 + 30;

template <typename T>
struct SegmentTree{
    struct node{
        T val;
        T add_lazy, assign_lazy;
        bool isAdded, isAssigned;
        node(){
            add_lazy = assign_lazy = 0;
            isAdded = isAssigned = false;
            val = 0;
        };
        node(T x){
            add_lazy = assign_lazy = 0;
            isAdded = isAssigned = false;
            val = x;
        }
    };

    vector<node> tree;

    node neutral_element = node(1e6); // e.g. 0 for sum, INF for min ...;

    inline void combine(node &par, node lf, node rg){
        par.val = min(lf.val, rg.val);
    }

    int _begin, _end;

    inline void init(int n){
        _begin = 0;
        _end = n - 1;
        tree.assign(n * 4 + 5, neutral_element);
    }

    inline void upd(int v, char op, T lazy){
        if (op == '='){
            tree[v].val = lazy;
            tree[v].assign_lazy = lazy;
            tree[v].isAssigned = true;

            tree[v].add_lazy = 0;
            tree[v].isAdded = false;
        }
        if (op == '+'){
            tree[v].val += lazy;
            tree[v].add_lazy += lazy;
            tree[v].isAdded = true;
        }
    }

    inline void push(int v, int tl, int tr){
        if (tl == tr) return;

        if (tree[v].isAssigned){
            upd(v << 1, '=', tree[v].assign_lazy);
            upd(v << 1 | 1, '=', tree[v].assign_lazy);
            tree[v].isAssigned = false;
            tree[v].assign_lazy = 0;
        }
        if (tree[v].isAdded){
            upd(v << 1, '+', tree[v].add_lazy);
            upd(v << 1 | 1, '+', tree[v].add_lazy);
            tree[v].isAdded = false;
            tree[v].add_lazy = 0;
        }

    }

    inline void update(int v, int tl, int tr, int l, int r, char op, T val){
        push(v, tl, tr);
        if (l <= tl && tr <= r){
            upd(v, op, val);
            return;
        }
        if (tl > r || tr < l) return;

        int tm = (tl + tr) >> 1;
        update(v << 1, tl, tm, l, r, op, val);
        update(v << 1 | 1, tm + 1, tr, l, r, op, val);

        combine(tree[v], tree[v << 1], tree[v << 1 | 1]);
    }

    inline void update(int l, int r, char op, T val){
        update(1, _begin, _end, l, r, op, val);
    }

    inline void update(int pos, char op, T val){
        update(1, _begin, _end, pos, pos, op, val);
    }

    inline node get(int v, int tl, int tr, int l, int r){
        push(v, tl, tr);
        if (l <= tl && tr <= r) return tree[v];
        if (tl > r || tr < l) return neutral_element;
        int tm = (tl + tr) >> 1;
        node res;
        combine(res, get(v << 1, tl, tm, l, r), get(v << 1 | 1, tm + 1, tr, l, r));
        return res;
    }

    inline node get(int l, int r){
        return get(1, _begin, _end, l, r);
    }

    int find(int v, int tl, int tr, int k){
        push(v, tl, tr);
        if (tl == tr) return tl;
        int tm = (tl + tr) >> 1;
        if (tree[v << 1].val > k){
            return find(v << 1, tl, tm, k);
        } else {
            return find(v << 1 | 1, tm + 1, tr, k);
        }
    }

    int find(int k){
        if (tree[1].val <= k) return -1;
        return find(1, _begin, _end, k);
    }

};

int a[N];
int ord[N];

void solve(){
    int n, m;
    cin >> n >> m;

    for (int i = 1; i <= n; i++) cin >> a[i];

    vector<int> p(n + 1);
    iota(all(p), 0);

    sort(all(p), [&](int i, int j){
        return MP(a[i] - 1LL * i * m, -i) < MP(a[j] - 1LL * j * m, -j);
    });

    for (int i = 0; i <= n; i++) ord[p[i]] = i;

    SegmentTree<int> st;
    st.init(n + 1);

    st.update(ord[0], '=', 0);

    for (int i = 1; i <= n; i++){
        int j = ord[i];

        int new_dp = st.get(j, n).val;

        st.update(0, n, '+', 1);

        if (new_dp <= n){
            int pos = st.find(new_dp);
            if (pos != -1 && pos <= j) st.update(pos, j, '=', new_dp);
        }

//        for (int t = 0; t <= n; t++){cout << st.get(t, t).val << ' ';} cout << endl;

    }

    cout << st.get(0, n).val << endl;

}

int main(){
    clock_t startTime = clock();
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    int test_cases = 1;
//    cin >> test_cases;

    for (int test = 1; test <= test_cases; test++){
        //cout << (solve() ? "YES" : "NO") << endl;
        solve();
    }

#ifdef LOCAL
    cerr << "Time: " << int((double) (clock() - startTime) / CLOCKS_PER_SEC * 1000) << " ms" << endl;
#endif

    return 0;
}

Compilation message (stderr)

triusis.cpp: In function 'int main()':
triusis.cpp:188:13: warning: unused variable 'startTime' [-Wunused-variable]
  188 |     clock_t startTime = clock();
      |             ^~~~~~~~~

• Subtask 1: 0 / 14
• Subtask 2: 0 / 21
• Subtask 3: 0 / 28
• Subtask 4: 0 / 37