Submission #1292184

#	Time	Username	Problem	Language	Result	Execution time	Memory
1292184		adscoding	Feast (NOI19_feast)	C++20	100 / 100	86 ms	12152 KiB

feast

#include <bits/stdc++.h>
#define int long long
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define BIT(mask, x) ((mask >> (x)) & 1)
#define FOR(i, a, b) for (int i = a, _b = b; i <= _b; ++i)
#define FORD(i, a, b) for (int i = a, _b = b; i >= _b; --i)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define dbg(...) cerr << "[" << #__VA_ARGS__ << "] = ", debug(__VA_ARGS__)
template<typename T> void debug(T x) { cerr << x << "\n"; }
template<typename T, typename... Args> void debug(T x, Args... args) {
    cerr << x << ", "; debug(args...);
}


// -------------------------------------- CON CUA BO HCN --------------------------------------

const int maxn = 3e5 + 3;
int n, a[maxn], K;
pll dp[maxn][2];

// --------------------------------------------------------------------------------------------

pll check(const int lmb)
{
    FOR(i, 1, n)
    {
        dp[i][0] = max(dp[i - 1][0], dp[i - 1][1]);
        dp[i][1] = max(pll(dp[i - 1][0].fi + a[i] - lmb, dp[i - 1][0].se + 1), pll(dp[i - 1][1].fi + a[i], dp[i - 1][1].se));
    }
    return max(dp[n][0], dp[n][1]);
}

void solve()
{
    cin >> n >> K;
    FOR(i, 1, n) cin >> a[i];
    dp[0][1] = {-1e15, -1e15};

    ll l = 1, r = 1e15;
    while (l <= r)
    {
        ll mid = l + r >> 1;
        if (check(mid).second >= K) l = mid + 1;
        else r = mid - 1;
    }   

    cout << check(r).first + K * r;
}

signed main()
{
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    #define TASK "TEST"
    if (fopen(TASK".INP", "r"))
    {
        freopen(TASK".INP", "r", stdin);
        freopen(TASK".OUT", "w", stdout);
    }
    solve();
    return 0;
}

/* NOTES:

*/

Compilation message (stderr)

feast.cpp: In function 'int main()':
feast.cpp:63:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |         freopen(TASK".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
feast.cpp:64:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |         freopen(TASK".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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