Submission #42024

#	Time	Username	Problem	Language	Result	Execution time	Memory
42024		OneSubmissionMan	Split the sequence (APIO14_sequence)	C++11	0 / 100	2032 ms	3792 KiB

sequence

# include <bits/stdc++.h>

# define F first
# define S second
# define mp make_pair
// everything go according to my plan
# define pb push_back
# define sz(a) (int)(a.size())
# define vec vector
// shimkenttin kyzdary, dzyn, dzyn, dzyn...
# define y1    Y_U_NO_y1
# define left  Y_U_NO_left
# define right Y_U_NO_right

using namespace std;

typedef pair <int, int> pii;
typedef long long ll;
typedef long double ld;

const int Mod = (int)1e9 + 7;
const int MX = 1073741822;
const ll MXLL = 4e18;
const int Sz = 1110111;
// a pinch of soul
inline void Read_rap () {
  ios_base :: sync_with_stdio(0);
  cin.tie(0); cout.tie(0);
}
inline void randomizer3000 () {
  unsigned int seed;
  asm ("rdtsc" : "=A"(seed));
  srand (seed);
}
void files (string problem) {
  if (fopen ((problem + ".in").c_str(),"r")) {
    freopen ((problem + ".in").c_str(),"r",stdin);
    freopen ((problem + ".out").c_str(),"w",stdout);
  }
}
void localInput (string in = "s") {
  if (fopen (in.c_str(), "r"))
    freopen (in.c_str(), "r", stdin);
  else {
    cerr << "Input file not found" << endl;
  }
}    
const int K = 200 + 1;
const int N = 1e5 + 1;

int n;
int k;

ll pref[Sz];

int a[Sz];
             
int pr[K][N];

struct CHT {
	struct line {
		ll k, b;      
		ll get (ll x) {
			return k * x + b;
		}
	};
	vec<line> r;
	vec<int> id;
	int ptr;

	CHT() : ptr(0) {}
	void clear() {
		r.clear();
		id.clear();
		ptr = 0;
	}  
	ld intersection (line &a, line &b) {
		return ((ld)b.b - a.b) / ((ld)a.k - b.k);
	}     	
	void add_line (line last, int Id) {
		while (sz(r) >= 2 && intersection (r[sz(r) - 2], r[sz(r)-1]) > intersection (r[sz(r)-2], last)) {
			r.pop_back();
			id.pop_back();
		}	
		r.pb (last);
		id.pb (Id);
	}
	pair <ll, int> get (ll x) {   
		ptr = min (ptr, sz(r) - 1);
		while (ptr + 1 < sz(r) && intersection (r[ptr], r[ptr + 1]) < x)
			ptr++;
		return {r[ptr].get (x), id[ptr]};
	}
};

int main()
{
  Read_rap();
 	localInput();
  cin >> n >> k;   
  for (int i = 1; i <= n; i++)
  	cin >> a[i];
  for (int i = 1; i <= n; i++)
  	pref[i] = pref[i - 1] + a[i];	
  ll dp[n + 1] = {0}, nw[n + 1] = {0};
  CHT T;
  /*
  for (int i = 1; i <= k; i++) {
  	T.clear();
  	for (int j = i + 1; j <= n; j++) {
  		j--;
  		T.add_line ( {pref[j], -pref[j] * pref[j] + dp[j]}, j);
  		j++;
    	tie (nw[j], pr[i][j]) = T.get (pref[j]); 
  	}
  	for (int j = 1; j <= n; j++)
  		dp[j] = nw[j];
  	for (int j = 1; j <= n; j++)
  		cout << dp[j] << ' ';
  	cout << endl;	
  }
  */
  {
  	for (int i = 1; i <= k; i++) {
			for (int j = i+1; j <= n; j++) {
				nw[j] = -1;
				for (int p = i; p < j; p++) {
					ll val = dp[p] + pref[p] * (pref[j] - pref[p]);
					if (val > nw[j]) {
						nw[j] = val;
						pr[i][j] = p;
					}
				}
			}    
			for (int j = 1; j <= n; j++)
				dp[j] = nw[j];
		}
	}          
  cout << dp[n] << endl;
    
  for (int i = k, j = n; i >= 1; ) {
  	j = pr[i][j]; 
  	i--;     
  	assert (j);
  	cout << j << ' ';
  }   	
  			

  return 0;
}










// Coded by Z..

Compilation message (stderr)

sequence.cpp: In function 'void files(std::__cxx11::string)':
sequence.cpp:37:50: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     freopen ((problem + ".in").c_str(),"r",stdin);
                                                  ^
sequence.cpp:38:52: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     freopen ((problem + ".out").c_str(),"w",stdout);
                                                    ^
sequence.cpp: In function 'void localInput(std::__cxx11::string)':
sequence.cpp:43:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     freopen (in.c_str(), "r", stdin);
                                     ^

• Subtask 1: 0 / 11
• Subtask 2: 0 / 11
• Subtask 3: 0 / 11
• Subtask 4: 0 / 17
• Subtask 5: 0 / 21
• Subtask 6: 0 / 29