Submission #402798

#	Time	Username	Problem	Language	Result	Execution time	Memory
402798		yoavL	Bali Sculptures (APIO15_sculpture)	C++14	9 / 100	34 ms	8316 KiB

sculpture

#include <iostream>
#include <vector>
#include <algorithm>

#define upmax(a, b) a = max(a, b);
#define upmin(a, b) a = min(a, b);
#define pr(x) cout << x << endl;

using namespace std;
using ll = long long;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;

const ll inf = 1e18;
const ll maxn = 1026; // each one is smaller than 10. so sum is no more than 500. Which means maxn's last bit is no more than 1023.
const ll maxg = 20;
ll n, a, b;
vll arr;
ll ans;
vll s;

void brute(vll& div, ll ind)
{
	if (ind == n) {
		if (div.size() < a-1 || div.size() > b-1) return;
		ll res = 0;
		ll cursum = 0;
		ll p = 0;
		for (ll i = 0; i < n; i++) {
			cursum += arr[i];
			if (p < div.size() && div[p] == i) {
				res |= cursum;
				p++;
				cursum = 0;
			}
		}
		res |= cursum;
		upmin(ans, res);
		return;
	}

	div.push_back(ind);
	if(ind < n-1) brute(div, ind + 1);
	div.pop_back();
	brute(div, ind + 1);
}


ll sum(ll l, ll r)
{
	ll res = s[r];
	if (l) res -= s[l - 1];
	return res;
}


ll calc_dp()
{
	
	/*
	dp[i][j][k] = is it possible to use first i vals to form j groups with OR-SUM equals k.
	*/

	vvvll dp(n+1, vvll(maxg + 1, vll(maxn, false)));

	dp[0][0][0] = true;


	for (ll i = 0; i <= n; i++) {
		for (ll j = 0; j <= maxg; j++) {
			for (ll k = 0; k < maxn; k++) {
				if (!dp[i][j][k]) continue;
				ll cursum = 0;
				for (ll m = i + 1; m <= n; m++) {
					cursum += arr[m - 1];
					if (cursum >= maxn) while (true);
					dp[m][j + 1][k | cursum] = 1;
				}
			}
		}
	}


	ll res = inf;
	for (ll j = a; j <= b; j++) {
		for (ll k = 0; k < maxn; k++) {
			if (dp[n][j][k]) upmin(res, k);
		}
	}
	return res;
}

int main()
{
	cin >> n >> a >> b;
	arr.resize(n);
	for (ll i = 0; i < n; i++) cin >> arr[i];
	s.resize(n);
	s[0] = arr[0];
	for (ll i = 1; i < n; i++) s[i] = arr[i] + s[i - 1];
	ans = inf;
	if (n <= 20) {

		vll div;
		brute(div, 0);
		pr(ans);
		return 0;
	}
	ans = calc_dp();
	pr(ans);
}

/*

6 1 3 
8 1 2 1 5 4


*/

Compilation message (stderr)

sculpture.cpp: In function 'void brute(vll&, ll)':
sculpture.cpp:26:18: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   26 |   if (div.size() < a-1 || div.size() > b-1) return;
      |       ~~~~~~~~~~~^~~~~
sculpture.cpp:26:38: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   26 |   if (div.size() < a-1 || div.size() > b-1) return;
      |                           ~~~~~~~~~~~^~~~~
sculpture.cpp:32:10: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |    if (p < div.size() && div[p] == i) {
      |        ~~^~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 0 / 16
• Subtask 3: 0 / 21
• Subtask 4: 0 / 25
• Subtask 5: 0 / 29