oj.uz

Submission #996608

# Submission time Handle Problem Language Result Execution time Memory
996608 2024-06-10T22:00:58 Z jklepec Sparklers (JOI17_sparklers) C++11
100 / 100
 154 ms 10940 KB 
#include <iostream>
#include <vector>
using namespace std;
#define int long long

typedef long long ll;
const int inf = 2e9;

int n, k, t;
vector<int> x;

vector<pair<ll, ll>> make_stack(vector<ll> v) {
    int N = v.size();

    vector<int> important(N);
    vector<ll> pref(N), mx_pr(N), mn_pr(N);

    ll mx_pref = 0, current_pref = 0;
    for (int i = 0; i < N; ++i) {
        current_pref += v[i];
        pref[i] = current_pref;
        mx_pref = max(mx_pref, pref[i]);
        if (pref[i] == mx_pref) important[i] = 1;
    }
    mx_pr[N - 1] = mn_pr[N - 1] = pref[N - 1];
    for (int i = N - 2; i >= 0; --i) {
        mx_pr[i] = max(pref[i], mx_pr[i + 1]);
        mn_pr[i] = min(pref[i], mn_pr[i + 1]);
    }

    vector<pair<ll, ll>> ret = {{0, 0}};
    for (int i = 0; i < N; ++i) {
        ret.back().first = min(ret.back().first, pref[i]);
        ret.back().second = pref[i];

        if (i < N - 1) {
            if (
                important[i] ||
                (pref[i] == mx_pr[i] &&
                 mx_pr[i] > mx_pr[i + 1] &&
                 mx_pr[i] != mx_pref &&
                 ret.back().first < mn_pr[i])
            )
            ret.push_back({pref[i], pref[i]});
        }
    }
    return ret;
}

bool check(int v) {
    // if ((ll) v * t > inf) return true;
    vector<ll> aa, bb;
    for (int i = k - 1; i >= 0; --i) {
        aa.push_back(2LL * v * t - (x[i + 1] - x[i]));
    }
    for (int i = k + 1; i < n; ++i) {
        bb.push_back(2LL * v * t - (x[i] - x[i - 1]));
    }
    // K = 1 or K = N
    aa.push_back(0); bb.push_back(0);

    vector<pair<ll, ll>> a = make_stack(aa);
    vector<pair<ll, ll>> b = make_stack(bb);

    int i = 0, j = 0;
    ll sum = 0;
    ll tmp_a = 0, tmp_b = 0;
    while (i < (int) a.size() || j < (int) b.size()) {
        bool can_a = false;
        bool can_b = false;
        if (i < (int) a.size() && tmp_a - a[i].first <= sum)
            can_a = true;
        if (j < (int) b.size() && tmp_b - b[j].first <= sum)
            can_b = true;

        if (can_a == can_b) {
            if (!can_a) return false;
            if (a[i].second >= tmp_a) can_b = false;
            else if (b[j].second >= tmp_b) can_a = false;
            else {
                ll nxt_a = a[i].second - a[i].first;
                ll nxt_b = b[j].second - b[j].first;
                if (nxt_a >= nxt_b) can_b = false;
                else can_a = false;
            }
        }

        if (can_a) {
            sum += a[i].second - tmp_a;
            tmp_a = a[i++].second;
        }
        else {
            sum += b[j].second - tmp_b;
            tmp_b = b[j++].second;
        }
        // cout << sum << " " << i << " " << j << endl << endl;
    }

    return true;
}

signed main() {
    cin >> n >> k >> t; --k;
    for (int i = 0; i < n; ++i) {
        int pos; cin >> pos;
        x.push_back(pos);
    }

    int lo = 0, hi = inf;
    while (lo < hi) {
        int mid = (lo + hi) >> 1;
        if (check(mid)) {
            hi = mid;
        }
        else {
            lo = mid + 1;
        }
    }
    cout << lo << endl;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 344 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 344 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 1 ms 348 KB Output is correct
14 Correct 1 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 344 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 344 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 1 ms 348 KB Output is correct
14 Correct 1 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 1 ms 344 KB Output is correct
23 Correct 1 ms 484 KB Output is correct
24 Correct 1 ms 348 KB Output is correct
25 Correct 1 ms 348 KB Output is correct
26 Correct 1 ms 348 KB Output is correct
27 Correct 1 ms 348 KB Output is correct
28 Correct 2 ms 344 KB Output is correct
29 Correct 1 ms 344 KB Output is correct
30 Correct 1 ms 348 KB Output is correct
31 Correct 1 ms 348 KB Output is correct
32 Correct 1 ms 348 KB Output is correct
33 Correct 1 ms 348 KB Output is correct
34 Correct 2 ms 444 KB Output is correct
35 Correct 1 ms 348 KB Output is correct
36 Correct 1 ms 348 KB Output is correct
37 Correct 1 ms 536 KB Output is correct
38 Correct 1 ms 440 KB Output is correct
39 Correct 1 ms 348 KB Output is correct
40 Correct 1 ms 348 KB Output is correct

Subtask #3
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 344 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 344 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 1 ms 348 KB Output is correct
14 Correct 1 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 1 ms 344 KB Output is correct
23 Correct 1 ms 484 KB Output is correct
24 Correct 1 ms 348 KB Output is correct
25 Correct 1 ms 348 KB Output is correct
26 Correct 1 ms 348 KB Output is correct
27 Correct 1 ms 348 KB Output is correct
28 Correct 2 ms 344 KB Output is correct
29 Correct 1 ms 344 KB Output is correct
30 Correct 1 ms 348 KB Output is correct
31 Correct 1 ms 348 KB Output is correct
32 Correct 1 ms 348 KB Output is correct
33 Correct 1 ms 348 KB Output is correct
34 Correct 2 ms 444 KB Output is correct
35 Correct 1 ms 348 KB Output is correct
36 Correct 1 ms 348 KB Output is correct
37 Correct 1 ms 536 KB Output is correct
38 Correct 1 ms 440 KB Output is correct
39 Correct 1 ms 348 KB Output is correct
40 Correct 1 ms 348 KB Output is correct
41 Correct 92 ms 5976 KB Output is correct
42 Correct 3 ms 700 KB Output is correct
43 Correct 29 ms 1892 KB Output is correct
44 Correct 127 ms 10564 KB Output is correct
45 Correct 135 ms 7944 KB Output is correct
46 Correct 123 ms 10068 KB Output is correct
47 Correct 129 ms 10276 KB Output is correct
48 Correct 109 ms 8152 KB Output is correct
49 Correct 127 ms 10664 KB Output is correct
50 Correct 104 ms 7752 KB Output is correct
51 Correct 118 ms 10240 KB Output is correct
52 Correct 123 ms 10052 KB Output is correct
53 Correct 136 ms 10656 KB Output is correct
54 Correct 135 ms 10940 KB Output is correct
55 Correct 104 ms 7896 KB Output is correct
56 Correct 121 ms 10252 KB Output is correct
57 Correct 154 ms 10184 KB Output is correct
58 Correct 112 ms 8188 KB Output is correct
59 Correct 114 ms 7236 KB Output is correct
60 Correct 117 ms 10032 KB Output is correct
61 Correct 126 ms 9764 KB Output is correct
62 Correct 107 ms 10352 KB Output is correct
63 Correct 122 ms 9220 KB Output is correct
64 Correct 102 ms 7580 KB Output is correct
65 Correct 99 ms 8064 KB Output is correct
66 Correct 103 ms 7640 KB Output is correct
67 Correct 102 ms 8356 KB Output is correct
68 Correct 122 ms 9972 KB Output is correct
69 Correct 125 ms 10068 KB Output is correct