Submission #951309

#	Time	Username	Problem	Language	Result	Execution time	Memory
951309		AndreyPavlov	The short shank; Redemption (BOI21_prison)	C++17	0 / 100	1 ms	348 KiB

prison

#include <bits/stdc++.h>

/* Using libraries */
using namespace std;

using ld = long double;
template <class T>
using vc = vector <T>;
using pii = pair <int, int>;
using pint = pair <int, int>;
template<class T>
bool chmax(T &a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

template<class T>
bool chmin(T &a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}

const int N = 5e5;
const int inf = 1e9;
int a[N], t, n;


pii check (int x) {
    vc <pii> dp(n + 1, {inf, 0});
    auto cmp = [&](pii a, pii b) {
        if (a.first + a.second * x == b.first + b.second * x)
            return a.second < b.second;
        return a.first + a.second * x < b.first + b.second * x;
    };
    dp[0] = {0, 0};
    for (int i = 0; i < n; ++i) {
        int mn = a[i], cnt = 0;
        for (int j = i; j < n; ++j) {
            if (mn <= t) {
                ++cnt;
            }
            dp[j + 1] = min(dp[j + 1], {dp[i].first + cnt, dp[i].second + 1}, cmp);
            if (j < n - 1)
                mn = min(mn + 1, a[j + 1]);
        }
    }
    return dp[n];
}

void solve() {
    int d;
    cin >> n >> d >> t;
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
    }
    int l = -1, r = inf;
    while (r - l > 1) {
        int m = (l + r) / 2;
        pii v = check(m);
        if (v.second - 1 <= d) {
            r = m;
        } else {
            l = m;
        }
    }
    pii v = check(r);
    cout << v.first << '\n';
}


signed main() {
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    int t = 1;
    // cin >> t;
    while (t--) solve();
}

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