Submission #155502

#	Time	Username	Problem	Language	Result	Execution time	Memory
155502		qkxwsm	Intergalactic ship (IZhO19_xorsum)	C++14	0 / 100	690 ms	8336 KiB

xorsum

#include <bits/stdc++.h>

using namespace std;

template<class T, class U>
void ckmin(T &a, U b)
{
	if (a > b) a = b;
}
template<class T, class U>
void ckmax(T &a, U b)
{
	if (a < b) a = b;
}

#define MP make_pair
#define PB push_back
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define FOR(i, a, b) for (auto i = (a); i < (b); i++)
#define FORD(i, a, b) for (auto i = (a) - 1; i >= (b); i--)
#define SZ(x) ((int) ((x).size()))
#define ALL(x) (x).begin(), (x).end()
#define INF 1000000007
#define MAXN 1013
#define MAXQ 100013

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vpi;
typedef vector<pll> vpl;

ll i2 = (INF + 1) >> 1;
int N, Q, M = 128;
int arr[MAXN];
ll ev[MAXN][MAXN];
vi guys[MAXN];
array<ll, 128> prob, tmp;
array<int, 3> quer[MAXQ];
ll ans;

void conv(int x)
{
	FOR(i, 0, M)
	{
		tmp[i] = (prob[i] + prob[i ^ x]) * i2;
		tmp[i] %= INF;
	}
	FOR(i, 0, M)
	{
		prob[i] = tmp[i];
	}
	return;
}

int32_t main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	cin >> N;
	FOR(i, 0, N)
	{
		cin >> arr[i];
	}
	cin >> Q;
	FOR(i, 0, Q)
	{
		int l, r, x;
		cin >> l >> r >> x; l--; r--;
		quer[i] = {l, r, x};
		guys[r].PB(i);
	}
	FOR(i, 0, N)
	{
		FOR(j, 0, M)
		{
			prob[j] = 0;
		}
		prob[0] = 1;
		FORD(j, N, i)
		{
			//convolve!
			for (int idx : quer[j])
			{
				int l = quer[idx][0], v = quer[idx][2];
				if (l > i) continue;
				conv(v);
			}
			FOR(k, 0, M)
			{
				ev[i][j] += (prob[k]) * (arr[i] ^ k) * (arr[j] ^ k);
			}
		}
	}
	//now we just need expected values of products.
	FOR(i, 0, N)
	{
		FOR(j, 0, i)
		{
			ev[i][j] = ev[j][i];
		}
	}
	FOR(i, 0, N)
	{
		FOR(j, 0, N)
		{
			ans += ev[i][j] * min((N - i) * (j + 1), (N - j) * (i + 1));
			ans %= INF;
		}
	}
	FOR(i, 0, Q)
	{
		ans += ans; if (ans >= INF) ans -= INF;
	}
	cout << ans << '\n';
	return 0;
}

• Subtask 1: 0 / 4
• Subtask 2: 0 / 5
• Subtask 3: 0 / 6
• Subtask 4: 0 / 9
• Subtask 5: 0 / 8
• Subtask 6: 0 / 11
• Subtask 7: 0 / 19
• Subtask 8: 0 / 30
• Subtask 9: 0 / 8