Submission #791366

#	Time	Username	Problem	Language	Result	Execution time	Memory
791366		SteGG	Feast (NOI19_feast)	C++17	71 / 100	1092 ms	53204 KiB

feast

//Judges with GCC >= 12 only needs Ofast
//#pragma GCC optimize("O3,no-stack-protector,fast-math,unroll-loops,tree-vectorize")
//MLE optimization
//#pragma GCC optimize("conserve-stack")
//Old judges
//#pragma GCC target("sse4.2,popcnt,lzcnt,abm,mmx,fma,bmi,bmi2")
//New judges. Test with assert(__builtin_cpu_supports("avx2"));
//#pragma GCC target("arch=skylake")
//Atcoder
//#pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma")
#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
//using namespace __gnu_pbds;

//template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

//write variables and debug
#define bugf cout << "Here" << endl
#define bug(...) _dbg(#__VA_ARGS__, __VA_ARGS__)
#define bugarr(arr,...) cout << #arr; _dbg_arr(arr, __VA_ARGS__)

template<class T, class U>
ostream& operator<<(ostream& output, const pair<T, U> &A){
	output << "(" << A.first << ", " << A.second <<  ")";
	return output;
}

template <class T>
ostream& operator<<(ostream& output, const vector<T> &arr){
	int n = arr.size();
	output << "[";
	for(int i = 0; i < n; i++){
		output << arr[i];
		if(i != n - 1) output << ", ";
	}
	output << "]";
	return output;
}

template<class T>
ostream& operator<<(ostream& output, const set<T> &s){
	output << "{";
	for(auto it = s.begin(); it != s.end(); it++){
		if(it != s.begin()) output << ", ";
		output << (*it);
	}
	output << "}";
	return output;
}

template<class T, class U>
ostream& operator<<(ostream& output, const map<T, U> &m){
	output << "{";
	for(auto it = m.begin(); it != m.end(); it++){
		if(it != m.begin()) output << ", ";
		output << "(" << it->first << " : " << it->second << ")";
	}
	output << "}";
	return output;
}

template<class TH>
void _dbg(const char *sdbg, TH h){
	cout << sdbg << " = " << h << endl;
}

template<class TH, class... TA>
void _dbg(const char *sdbg, TH h, TA... a) {
	while(*sdbg != ',')cout << *sdbg++;
	cout << " = " << h << "\n";
	_dbg(sdbg+1, a...);
}

template<class _Arr, class _Index>
void _dbg_arr(_Arr arr, _Index index){
	cout << '[' << index << "] = " << arr[index] << endl;
}

template<class _Arr, class _Index, class... TA>
void _dbg_arr(_Arr &arr, _Index index, TA... args){
	cout << '[' << index << ']';
	_dbg_arr(arr[index], args...);
}

//open file
#define taskname "" //name input and output file

#ifdef SteGG
void open(){
	if(fopen("input.inp", "r")){
		freopen("input.inp", "r", stdin);
		//freopen("output.out", "w", stdout);
	}
}
#else
void open(){
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
		freopen(taskname".out", "w", stdout);
	}
}
#endif

//initialize
#define testcase \
	long long test; \
	cin >> test; \
	for(int tst = 1; tst <= test; tst++)
#define int long long
#define MOD 1000000007
#define FFTMOD (119 << 23 | 1)
#define EPSILON 1e-9
#define setpre(x) fixed << setprecision(x)
#define cd complex<double>
#define all(x) x.begin(), x.end()

const long long INF = 3e18L + 5;
const int inf = 1e9 + 7;
const double infd = 1e60;
const double PI = acos(-1);
const int maxn = 3e5 + 5;
//const int base = ;
int n, k;
int arr[maxn];
int dp[2001][2001][2];

//others struct or class

//others function

//others init

signed main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	open();
	cin >> n >> k;

	int cnt = 0;

	for(int i = 1; i <= n; i++){
		cin >> arr[i];
		if(arr[i] < 0) cnt++;
	}


	if(k == 1){
		int best = 0;
		int cur = 0;
		for(int i = 1; i <= n; i++){
			cur += arr[i];
			if(cur > best){
				best = cur;
			}

			if(cur < 0) cur = 0;
		}

		cout << best << endl;
	}else if(cnt == 0){
		int result = 0;
		for(int i = 1; i <= n; i++){
			result += arr[i];
		}

		cout << result << endl;
	}else if(cnt == 1){
		int result = 0;
		for(int i = 1; i <= n; i++){
			if(arr[i] >= 0) result += arr[i];
		}

		cout << result << endl;
	}else{
		for(int i = 1; i <= k; i++){
			for(int j = 1; j <= n; j++){
				dp[i][j][0] = max(dp[i - 1][j - 1][1], dp[i][j - 1][0]);
				dp[i][j][1] = max({dp[i][j - 1][0], dp[i][j - 1][1], dp[i - 1][j - 1][1]}) + arr[j];
			}
		}

		int result = 0;
		for(int i = 1; i <= n; i++){
			result = max(result, dp[k][i][1]);
		}

		cout << result << endl;
	}



	return 0;
}

Compilation message (stderr)

feast.cpp: In function 'void open()':
feast.cpp:101:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  101 |   freopen(taskname".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
feast.cpp:102:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  102 |   freopen(taskname".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: 0 / 29