Submission #336721

#	Time	Username	Problem	Language	Result	Execution time	Memory
336721		amoo_safar	Candies (JOI18_candies)	C++17	0 / 100	2 ms	876 KiB

candies

// vaziat meshki-ghermeze !
#include <bits/stdc++.h>

#define pb push_back
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " : " << x << '\n'

using namespace std;

typedef long long ll;
typedef long double ld;
typedef string str;
typedef pair<ll, ll> pll;

const ll Mod = 1000000007LL;
const int N = 2e3 + 10;
const ll Inf = 2242545357980376863LL;
const ll Log = 30;

ll a[N];

vector<ll> dp[2][2][N];

void Divide(int id, int L, int R){
	// cerr << "S " << L << " " << R << '\n';
	if(L + 1 == R){
		dp[0][0][id] = {0};
		dp[1][1][id] = {0, a[L]};
		dp[0][1][id] = {0};
		dp[1][0][id] = {0};
		return ;
	}
	int mid = (L + R) >> 1;

	Divide(id << 1, L, mid);
	Divide(id << 1 | 1, mid, R);
	for(int i = 0; i < 4; i++){
		dp[i>>1&1][i&1][id].resize(1, 0);
		dp[i>>1&1][i&1][id].resize(R - L + 1, -Inf);
	}
	for(int mkl = 0; mkl < 4; mkl ++){
		for(int mkr = 0; mkr < 4; mkr ++){
			int l = mkl >> 1 & 1, i = mkl & 1, j = mkr >> 1 & 1, r = mkr & 1;
			if(i + j > 1) continue;
			// cerr << l << i << j << r << '\n';
			int pl = 0, pr = 0;
			vector<ll> &lc = dp[l][i][id << 1];
			vector<ll> &rc = dp[j][r][id << 1|1]; 
			while((pl + 1 < lc.size()) || (pr + 1 < rc.size())){
				int fl = -1;
				if(pl + 1 == lc.size()){
					fl = 1;
				} else if(pr + 1 == rc.size()){
					fl = 0;
				} else {
					if(lc[pl + 1] - lc[pl] >= rc[pr + 1] - rc[pr])
						fl = 0;
					else fl = 1;
				}
				if(fl) pr ++;
				else pl ++;
				dp[l][r][id][pl + pr] = max(dp[l][r][id][pl + pr], lc[pl] + rc[pr]);
			}
		}
	}
	// cerr << "Combed\n";
	for(int i = 0; i < 4; i++){
		dp[i>>1&1][i&1][id<<1].clear();
		dp[i>>1&1][i&1][id<<1].shrink_to_fit();
		dp[i>>1&1][i&1][id<<1|1].clear();
		dp[i>>1&1][i&1][id<<1|1].shrink_to_fit();
	}
	if(id > 1){
		for(int i = 0; i < 4; i++){
			while(!dp[i>>1&1][i&1][id].empty() && dp[i>>1&1][i&1][id].back() < 0)
				dp[i>>1&1][i&1][id].pop_back();
		}
	}
	// cerr << "double\n";
	return ;
}

int main(){
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	
	int n;
	cin >> n;

	for(int i = 1; i <= n; i++){
		cin >> a[i];
	}


	int sz = (n + 1) / 2;
	Divide(1, 1, n + 1);

	for(int i = 1; i <= sz; i++){
		ll mx = -Inf;
		for(int mk = 0; mk < 4; mk ++)
			mx = max(mx, dp[mk&1][mk>>1 & 1][1][i]);
		cout << mx << '\n';
	}
	return 0;
}

Compilation message (stderr)

candies.cpp: In function 'void Divide(int, int, int)':
candies.cpp:51:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |    while((pl + 1 < lc.size()) || (pr + 1 < rc.size())){
      |           ~~~~~~~^~~~~~~~~~~
candies.cpp:51:42: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |    while((pl + 1 < lc.size()) || (pr + 1 < rc.size())){
      |                                   ~~~~~~~^~~~~~~~~~~
candies.cpp:53:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |     if(pl + 1 == lc.size()){
      |        ~~~~~~~^~~~~~~~~~~~
candies.cpp:55:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |     } else if(pr + 1 == rc.size()){
      |               ~~~~~~~^~~~~~~~~~~~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 92