Submission #257482

#	Time	Username	Problem	Language	Result	Execution time	Memory
257482		karma	Feast (NOI19_feast)	C++14	30 / 100	137 ms	13440 KiB

feast

#include <bits/stdc++.h>
#define pb          emplace_back
#define ll          long long
#define fi          first
#define se          second
#define mp          make_pair
//#define int         int64_t

using namespace std;

const int N = int(6e5) + 7;
typedef pair<int, int> pii;

ll f[N][2];
int cnt[N][2], n, k, a[N];

/// 0 - ok
/// 1 - opening

int check(ll mid) {
    f[0][0] = 0, f[0][1] = -mid;
    cnt[0][0] = 0, cnt[0][1] = 1;
    for(int i = 1; i <= n; ++i) {
        if(f[i - 1][0] > f[i - 1][1] + a[i]) {
            f[i][0] = f[i - 1][0];
            cnt[i][0] = cnt[i - 1][0];
        } else if(f[i - 1][0] < f[i - 1][1] + a[i]) {
            f[i][0] = f[i - 1][1] + a[i];
            cnt[i][0] = cnt[i - 1][1];
        } else {
            f[i][0] = f[i - 1][0];
            cnt[i][0] = max(cnt[i - 1][0], cnt[i - 1][1]);
        }
        if(f[i - 1][1] + a[i] > f[i - 1][0] + a[i] - mid) {
            f[i][1] = f[i - 1][1] + a[i];
            cnt[i][1] = cnt[i - 1][1];
        } else if(f[i - 1][1] + a[i] < f[i - 1][0] + a[i] - mid) {
            f[i][1] = f[i - 1][0] + a[i] - mid;
            cnt[i][1] = cnt[i - 1][0] + 1;
        } else {
            f[i][1] = f[i - 1][1] + a[i];
            cnt[i][1] = max(cnt[i - 1][0] + 1, cnt[i - 1][1]);
        }
    }
    return cnt[n][0];
}

int32_t main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    #define Task        "test"
    if(fopen(Task".inp", "r")) {
        freopen(Task".inp", "r", stdin);
        freopen(Task".out", "w", stdout);
    }
    cin >> n >> k;
    for(int i = 1; i <= n; ++i) cin >> a[i];
    n += k;
    ll low = 1, mid, high = 1e15;
    while(low <= high) {
        mid = (low + high) >> 1;
        if(check(mid) >= k) low = mid + 1;
        else high = mid - 1;
    }
    check(high);
    cout << f[n][0] + 1ll * high * k;
}

Compilation message (stderr)

feast.cpp: In function 'int32_t main()':
feast.cpp:53:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         freopen(Task".inp", "r", stdin);
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
feast.cpp:54:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         freopen(Task".out", "w", stdout);
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 18 / 18
• Subtask 4: 0 / 10
• Subtask 5: 0 / 11
• Subtask 6: 0 / 20
• Subtask 7: 0 / 29