Submission #923027

#	Time	Username	Problem	Language	Result	Execution time	Memory
923027		penguin133	Bootfall (IZhO17_bootfall)	C++17	28 / 100	1075 ms	38996 KiB

bootfall

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define pi pair<int, int>
#define pii pair<int, pi>
#define fi first
#define se second
#ifdef _WIN32
#define getchar_unlocked _getchar_nolock
#endif
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

bitset <501*501*2>dp[505], dp2[505];
int n, A[505];
const int os = 500 * 500;

bool chk(int a, int b){
	if(os - a - b >= 0 && dp[n & 1][os - a - b])return 1;
	if(os - a + b >= 0 && os - a + b <= 2 * os && dp[n & 1][os - a + b])return 1;
	if(os + a - b >= 0 && os + a - b <= 2 * os && dp[n & 1][os + a - b])return 1;
	if(os + a + b <= 2 * os && dp[n & 1][os + a + b])return 1;
	return 0;
}

void solve(){
	cin >> n;
	for(int i = 1; i <= n; i++)cin >> A[i];
	//for(int i = 0; i <= 2 * os; i++)dp[0][i] = 0
	dp[0][os] = dp2[n + 1][os] = 1;
	for(int i = 1; i <= n; i++){
		dp[i] |= (dp[i - 1] >> A[i]);
		dp[i] |= (dp[i - 1] << A[i]);
	}
	for(int i = n; i >= 1; i--){
		dp2[i] |= (dp2[i + 1] >> A[i]);
		dp2[i] |= (dp2[i + 1] << A[i]);
	}
	if(!dp[n][os]){
		cout << 0;
		return;
	}
	set <int> s;
	for(int i = 1; i <= os; i++)s.insert(i);
	for(int i = 1; i <= n; i++){
		/*
		bitset <501*501*2> tmp = dp[i - 1], tmp2;
		for(int j = 0; j <= os; j++){
			if(dp2[i + 1][os - j] || dp2[i + 1][os + j]){
				if(1)tmp2 |= (tmp >> j), tmp2 |= (tmp << j);
			}
		}
		*/
		bitset <501 * 501 * 2> tmp;
		tmp[os] = 1;
		for(int j = 1; j <= n; j++){
			if(j == i)continue;
			tmp = (tmp >> A[j]) | (tmp << A[j]);
		}
		for(int j = 0; j <= os; j++)if(!tmp[os - j] && !tmp[os + j])s.erase(j);
	}
	cout << (int)s.size() << '\n';
	for(auto i : s)cout << i << ' ';
}

main(){
	ios::sync_with_stdio(0);cin.tie(0);
	int tc = 1;
	//cin >> tc;
	for(int tc1=1;tc1<=tc;tc1++){
		// cout << "Case #" << tc1 << ": ";
		solve();
	}
}

Compilation message (stderr)

bootfall.cpp:66:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   66 | main(){
      | ^~~~

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 15 / 15
• Subtask 4: 0 / 16
• Subtask 5: 0 / 21
• Subtask 6: 0 / 35