Submission #855256

#	Time	Username	Problem	Language	Result	Execution time	Memory
855256		vjudge1	Split the sequence (APIO14_sequence)	C++17	0 / 100	2058 ms	2652 KiB

sequence

// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>

#define ordered_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
#define len(x) (int)x.size()
#define ull unsigned long long
#define F first
#define S second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define int long long
#define double long double
#define pii pair<int,int>

using namespace std;
using namespace __gnu_pbds;
using ll = long long;

const int N = 2e5 + 5;
const int MOD = 1e9 + 7;
const ll INF = 1e18;
const ll inf = 1e9;
int n,k,a[N],mx,p[N];
string ans;

void rec(int l = 1,int r = n,int idx = 0, int res = 0, string s = ""){
	if (idx == k){
		if (res > mx){
			mx = res;
			ans = s;
		}
		return;
	}
	for (int i=l;i<=r;i++){
		int cur = (p[i] - p[l-1]) * (p[r] - p[i]);
		rec(l, i,idx + 1, res + cur, s + char(i + 1 + '0'));
		rec(i + 1, r, idx + 1, res + cur, s + char(i + '0'));
	}
}

main(){
	// freopen("txt.in", "r", stdin);
	// freopen("txt.out", "w", stdout);
	ios_base::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	cin >> n >> k;
	for (int i=1;i<=n;i++){
		cin >> a[i];
		p[i] = p[i-1] + a[i];
	}
	rec();
	cout << mx << '\n';
	for (char c : ans){
		cout << c << ' ';
	}
}

//order_of_key(k): Number of items strictly smaller than k .
//find_by_order(k): K-th element in a set (counting from zero).

//sum of squares n*(n+1)*(2n+1)/6
//sum of cubes [n*(n+1)/2]^2
//sum of squares for odds n*(4*n*n-1)/3
//sum of cubes for odds n*n*(2*n*n-1)

//a/b%mod = a*(b^(m-2)%mod)
//(a>>x)&1 == 0
//a^b = (a+b)-2(a&b)

//srand(time(0))-always changing

Compilation message (stderr)

sequence.cpp:46:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   46 | main(){
      | ^~~~

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