Submission #1279039

#	Time	Username	Problem	Language	Result	Execution time	Memory
1279039		swishy123	Rabbit Carrot (LMIO19_triusis)	C++20	100 / 100	69 ms	6696 KiB

triusis

#include <bits/stdc++.h>
#define ll long long

const int inf = 1e9;
using namespace std;

struct SegmentTreeFast{
    vector<int> a;
    int defv;
    int n;

    SegmentTreeFast(int n, int defv) : n(n), defv(defv){
        a = vector<int>(2 * n, defv);
    }
    int cmb(int a, int b){
        return max(a, b);
    }
    void build(){
        for (int i = n - 1; i > 0; --i)
            a[i] = cmb(a[i << 1], a[i << 1 | 1]);
    }
    void update(int i, int v){
        int val = a[i + n];
        for (a[i += n] = cmb(v, val); i > 1; i >>= 1)
            a[i >> 1] = cmb(a[i], a[i ^ 1]);
    }
    int get(int l, int r){
        r++;
        int res = defv;
        for (l += n, r += n; l < r; l >>= 1, r >>= 1){
            if (l&1) res = cmb(res, a[l++]);
            if (r&1) res = cmb(res, a[--r]);
        }
        return res;
    }
};

int get(vector<ll> a, int n, int m){
    for (int i = 0; i < n; i++)
        a[i] = a[i] - (ll)i * m;

    auto v = a;
    sort(v.begin(), v.end());

    SegmentTreeFast st(n, -1e9);
    int pos = lower_bound(v.begin(), v.end(), a[0]) - v.begin();

    st.update(pos, 1);
    for (int i = 1; i < n; i++){
        pos = lower_bound(v.begin(), v.end(), a[i]) - v.begin();
        int val = st.get(pos, n - 1);

        st.update(pos, val + 1);
    }
    int res = st.get(0, n - 1);
    return n - res;
}

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

    vector<ll> a(n, 0);
    for (int i = 0; i < n; i++)
        cin >> a[i];

    int res = n;
    if (a[0] <= m)
        res = min(res, get(a, n, m));
    a[0] = m;
    res = min(res, get(a, n, m) + 1);

    cout << res;
}

/*
-1 3 -1 1 0 -1

11 3 0 1 0 0

1 0 3 2
0 1 3 2 
*/

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

    if (ifstream("input.txt").good()){
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout); 
    }

    int t;
    t = 1;
    
    while (t--){
        solve();
        cout << '\n';
    }
}

Compilation message (stderr)

triusis.cpp: In function 'int main()':
triusis.cpp:90:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |         freopen("input.txt", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
triusis.cpp:91:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |         freopen("output.txt", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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