Submission #970994

#	Time	Username	Problem	Language	Result	Execution time	Memory
970994		vladilius	The short shank; Redemption (BOI21_prison)	C++17	35 / 100	2066 ms	75720 KiB

prison

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int inf = numeric_limits<int> :: max();

struct ST{
    vector<int> t, p;
    int n;
    ST(int ns){
        n = ns;
        t.resize(4 * n);
        p.resize(4 * n);
    }
    void push(int& v, int& vv){
        if (!p[v]) return;
        p[vv] += p[v]; t[vv] += p[v];
        p[vv + 1] += p[v]; t[vv + 1] += p[v];
        p[v] = 0;
    }
    void add(int v, int tl, int tr, int& l, int& r, int& x){
        if (l > tr || r < tl) return;
        if (l <= tl && tr <= r){
            t[v] += x;
            p[v] += x;
            return;
        }
        int tm = (tl + tr) / 2, vv = 2 * v;
        push(v, vv);
        add(vv, tl, tm, l, r, x);
        add(vv + 1, tm + 1, tr, l, r, x);
        t[v] = min(t[vv], t[vv + 1]);
    }
    void add(int l, int r, int x){
        if (l > r) return;
        add(1, 1, n, l, r, x);
    }
    int get(int v, int tl, int tr, int& l, int& r){
        if (l > tr || r < tl) return inf;
        if (l <= tl && tr <= r){
            return t[v];
        }
        int tm = (tl + tr) / 2, vv = 2 * v;
        push(v, vv);
        return min(get(vv, tl, tm, l, r), get(vv + 1, tm + 1, tr, l, r));
    }
    int get(int l, int r){
        if (l > r) return inf;
        return get(1, 1, n, l, r);
    }
};

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    
    int n, d, t; cin>>n>>d>>t;
    vector<int> a(n + 1);
    for (int i = 1; i <= n; i++){
        cin>>a[i];
    }
    vector<int> h(n + 1);
    priority_queue<int, vector<int>, greater<int>> pq;
    int tt = 0, cnt = 0;
    for (int j = 1; j <= n; j++){
        pq.push(a[j] - tt);
        int m = pq.top() + tt;
        cnt += (m <= t);
        h[j] = cnt;
        tt++;
    }
    
    vector<int> r(n + 1);
    for (int i = 1; i <= n; i++){
        if (a[i] > t) continue;
        int m = t - a[i];
        r[i] = i + m;
    }
    
    const int lg = ceil(log2(n));
    vector<vector<int>> sp(n + 1, vector<int>(lg));
    for (int i = 1; i <= n; i++){
        sp[i][0] = r[i];
    }
    for (int j = 1; j < lg; j++){
        for (int i = 1; i + (1 << j) <= n + 1; i++){
            sp[i][j] = max(sp[i][j - 1], sp[i + (1 << (j - 1))][j - 1]);
        }
    }
    vector<int> log(n + 1);
    for (int i = 2; i <= n; i++){
        log[i] = log[i / 2] + 1;
    }
    
    auto check = [&](int x, int y){
        int k = log[y - x + 1];
        return max(sp[x][k], sp[y - (1 << k) + 1][k]) >= y;
    };
    
    vector<int> f(n);
    for (int i = 1; i < n; i++){
        int j = 2;
        while (j <= i + 1 && check(j, i + 1)){
            j++;
        }
        f[i] = j - 1;
    }
 
    vector<vector<int>> dp(n + 1, vector<int>(d + 1));
    for (int i = 1; i <= n; i++){
        dp[i][0] = h[i];
    }
    for (int k = 1; k <= d; k++){
        ST T(n);
        for (int i = 1; i <= n; i++){
            T.add(1, f[i - 1] - 1, 1);
            dp[i][k] = min(dp[i][k - 1], T.get(1, i - 1));
            T.add(i, i, dp[i][k - 1]);
        }
    }

    cout<<dp[n][d]<<"\n";
}

• Subtask 1: 15 / 15
• Subtask 2: 0 / 10
• Subtask 3: 20 / 20
• Subtask 4: 0 / 10
• Subtask 5: 0 / 25
• Subtask 6: 0 / 20