Submission #348464

#	Time	Username	Problem	Language	Result	Execution time	Memory
348464		Kevin_Zhang_TW	Intergalactic ship (IZhO19_xorsum)	C++17	17 / 100	449 ms	492 KiB

xorsum

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define pb emplace_back
#define AI(i) begin(i), end(i)
template<class T> bool chmin(T &a, T b) { return b < a && (a = b, true); }
template<class T> bool chmax(T &a, T b) { return a < b && (a = b, true); }
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() { cerr << endl; }
template<class T, class ...U> void kout(T a, U ...b) { cerr << a << ' ', kout(b...); }
template<class T> void debug(T L, T R) { while (L != R) cerr << *L << " \n"[next(L) == R], ++L; }
#else
#define DE(...) 0
#define debug(...) 0
#endif

const int MAX_N = 1010, p = 1e9 + 7, MAX_Q = 100010;

int n, a[MAX_N], q, l[MAX_N], r[MAX_N], x[MAX_N];

ll pf[MAX_N], psq[MAX_N];

int brute_force() {

	ll res = 0;

	for (int s = 0;s < 1<<q;++s) {
		fill(pf, pf+n+1, 0);

		for (int i = 0;i < q;++i) if (s >> i & 1) 
			pf[ l[i] ] ^= x[i], pf[ r[i]+1 ] ^= x[i];

		for (int i = 1;i <= n;++i) 
			pf[i] ^= pf[i-1];

 		for (int i = 1;i <= n;++i) 
 			pf[i] = (pf[i] ^ a[i]) + pf[i-1];

  		for (int i = 1;i <= n;++i)
  			res = (res + pf[i] * pf[i] % p * (n + 1 )) % p;

		ll sum = accumulate(pf+1, pf+1+n, 0ll) % p;

		res = (res - sum * sum) % p;
	}

	if (res < 0) res += p;

	return res;
}
int32_t main() {
	ios_base::sync_with_stdio(0), cin.tie(0);

	cin >> n;

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

	cin >> q;

	for (int i = 0;i < q;++i)
		cin >> l[i] >> r[i] >> x[i];

	if (q > 20) return 1;

	cout << brute_force() << '\n';

}

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