Submission #1255148

#	Time	Username	Problem	Language	Result	Execution time	Memory
1255148		hungeazy	Feast (NOI19_feast)	C++20	100 / 100	110 ms	12172 KiB

feast

/*
* @Author: hungeazy
* @Date:   2025-08-08 22:07:03
* @Last Modified by:   hungeazy
* @Last Modified time: 2025-08-08 22:13:57
*/
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp> 
#include <ext/pb_ds/tree_policy.hpp> 
// #pragma GCC optimize("O3")  
// #pragma GCC optimize("unroll-loops")  
// #pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")  
using namespace std;
using namespace __gnu_pbds; 
bool M1;
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define int long long
#define ll long long 
#define ull unsigned long long
#define sz(x) x.size()
#define sqr(x) (1LL * (x) * (x))
#define all(x) x.begin(), x.end()
#define fill(f,x) memset(f,x,sizeof(f))
#define FOR(i,l,r) for(int i=l;i<=r;i++)
#define FOD(i,r,l) for(int i=r;i>=l;i--)
#define debug(x) cout << #x << " = " << x << '\n'
#define ii pair<int,int>
#define iii pair<int,ii>
#define di pair<ii,ii>
#define vi vector<int>
#define vii vector<ii>
#define mii map<int,int>
#define fi first
#define se second
#define pb push_back
#define MOD 1000000007
#define __lcm(a,b) (1ll * ((a) / __gcd((a), (b))) * (b))
#define YES cout << "YES\n"
#define NO cout << "NO\n"
#define MASK(i) (1LL << (i))
#define c_bit(i) __builtin_popcountll(i)
#define BIT(x,i) ((x) & MASK(i))
#define SET_ON(x,i) ((x) | MASK(i))
#define SET_OFF(x,i) ((x) & ~MASK(i))
#define oo 1e18
#define name ""
#define endl '\n'
#define memory() cerr << abs(&M2-&M1)/1024.0/1024 << " MB" << endl
#define time() cerr << endl << "-------------Time:" << 1000.0 * clock() / CLOCKS_PER_SEC << "ms." << endl
template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; }
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; }
template <class T> using ordered_set = tree <T, null_type, less_equal <T>, rb_tree_tag,tree_order_statistics_node_update>;
const int N = (int)3e5+10;
int n,k,a[N];

namespace hungeazy {

	ii dp[N][2];

	ii calc(int lambda)
	{
		dp[0][1] = {-oo,-oo};
		FOR(i,1,n)
		{
			dp[i][0] = max(dp[i-1][0],dp[i-1][1]);
			dp[i][1] = max(make_pair(dp[i-1][0].fi+a[i]-lambda,dp[i-1][0].se+1),
						   make_pair(dp[i-1][1].fi+a[i],dp[i-1][1].se));
		}
		return max(dp[n][0],dp[n][1]);
	}

	void solve(void)
	{
		int l = 1, r = 1e18, ans = 0;
		while (l <= r)
		{
			int mid = (l+r)>>1;
			if (calc(mid).se >= k) ans = mid, l = mid+1;
			else r = mid-1;
		}
		cout << calc(ans).fi+k*ans;
	}
	
}

bool M2;
signed main()
{
    fast;
    if (fopen(name".inp","r"))
    {
    	freopen(name".inp","r",stdin);
    	freopen(name".out","w",stdout);
    }
    cin >> n >> k;
    FOR(i,1,n) cin >> a[i];
    hungeazy::solve();
    time();
    memory();
    return 0;
}
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// ░  ░  ░   ░              ░       ░

Compilation message (stderr)

feast.cpp: In function 'int main()':
feast.cpp:92:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   92 |         freopen(name".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
feast.cpp:93:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   93 |         freopen(name".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