Submission #532381

#	Time	Username	Problem	Language	Result	Execution time	Memory
532381		4fecta	The short shank; Redemption (BOI21_prison)	C++17	35 / 100	195 ms	203616 KiB

prison

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define int ll
#define ld long double
#define pii pair<int, int>
#define f first
#define s second
#define boost() cin.tie(0), cin.sync_with_stdio(0)

const int MN = 4005;

int n, d, T, t[MN], cnt[MN][MN], dp[MN][MN];

void solve(int j, int l, int r, int p1, int p2) {
    int mid = (l + r) >> 1, opt = n + 1;
    for (int i = max(mid, p1); i <= p2; i++) {
        if (dp[mid][j] >= dp[i + 1][j - 1] + cnt[mid][i]) {
            dp[mid][j] = dp[i + 1][j - 1] + cnt[mid][i];
            opt = i;
        }
    }
    if (l == r) return;
    solve(j, mid + 1, r, opt, p2);
    solve(j, l, mid, p1, opt);
}

int32_t main() {
    boost();

    cin >> n >> d >> T;
    for (int i = 1; i <= n; i++) cin >> t[i];
    for (int i = 1; i <= n; i++) {
        int num = 0, mn = 0x3f3f3f3f;
        for (int j = i; j <= n; j++) {
            if (min(mn, t[j]) <= T) num++;
            cnt[i][j] = num;
            mn = min(mn, t[j]) + 1;
        }
    }
    memset(dp, 0x3f, sizeof(dp));
    dp[n + 1][0] = 0;
    for (int i = 1; i <= d + 1; i++) solve(i, 1, n, 1, n);
    printf("%lld\n", dp[1][d + 1]);

    return 0;
}

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