// Nurstan Duisengaliev(REALBOY)
// не, не надо меня узнавать
#pragma GCC target ("avx2")
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define ll long long
#define all(x) x.begin(), x.end()
#define in insert
#define mp make_pair
#define F first
#define S second
#define ppf pop_front
#define pb push_back
#define ppb pop_back
#define pf push_front
#define pii pair <int, int>
#define pll pair <ll, ll>
#define boost() ios_base::sync_with_stdio(0), cin.tie(0)
#define sz(x) (int)x.size()
#define int ll
using namespace std;
const int N = (int)1e6 + 123;
const int mod = (int)1e9 + 7;
const ll INF = (ll)1e18 + 1;
int n, a[N], c[N];
void calc (int B) {
if ((c[1] & (1 << B)) || !(c[n] & (1 << B))) return;
int pos = 0;
for (int i = 1; i <= n - 1; i ++) {
if ((c[i] & (1 << B)) == 0 && (c[i + 1] & (1 << B))) {
pos = i;
break;
}
}
vector <int> f, s;
for (int i = pos; i >= 1; i --) f.pb (c[i]);
for (int i = n; i > pos; i --) s.pb (c[i] ^ (1 << B));
int P = 1;
while (sz (f) + sz (s)) {
if (sz (f) == 0) {
c[P] = s.back();
s.ppb ();
}
else if (sz (s) == 0) {
c[P] = f.back ();
f.ppb ();
}
else {
if (f.back () < s.back ()) {
c[P] = f.back ();
f.ppb ();
}
else {
c[P] = s.back();
s.ppb ();
}
}
P ++;
}
assert (P == n + 1);
return;
}
void solve () {
cin >> n;
for (int i = 1; i <= n; i ++) {
cin >> a[i];
c[i] = a[i];
}
sort (c + 1, c + n + 1);
ll ans = 0;
for (int B = 29; B >= 0; B --) {
int r1 = n, l1 = n + 1, l2 = n + 1, r2 = n;
ll sum = 0;
for (int i = 1; i <= n; i ++) {
while (r1 >= 1 && c[r1] + c[i] > (1 << (B + 1)) - 1) r1 --;
while (l1 >= 2 && c[l1 - 1] + c[i] >= (1 << B)) l1 --;
if (l1 <= min (i, r1)) sum += (min (i, r1) - l1 + 1);
while (r2 >= 1 && c[r2] + c[i] > (1 << (B + 2)) - 1) r2 --;
while (l2 >= 2 && c[l2 - 1] + c[i] >= (1 << B) + (1 << (B + 1))) l2 --;
if (l2 <= min (i, r2)) sum += (min (i, r2) - l2 + 1);
}
if (sum % 2 == 1) ans ^= (1 << B);
calc (B);
}
cout << ans;
}
main () {
// freopen (".in", "r", stdin);
// freopen (".out", "w", stdout);
boost ();
int TT = 1;
// cin >> TT;
while (TT --) {
solve ();
}
return 0;
}
Compilation message
xorsum.cpp:95:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
95 | main () {
| ^
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
492 KB |
Output is correct |
2 |
Correct |
6 ms |
492 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
593 ms |
36812 KB |
Output is correct |
2 |
Correct |
542 ms |
34792 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
593 ms |
36812 KB |
Output is correct |
2 |
Correct |
542 ms |
34792 KB |
Output is correct |
3 |
Correct |
741 ms |
38980 KB |
Output is correct |
4 |
Correct |
786 ms |
37852 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
492 KB |
Output is correct |
2 |
Correct |
6 ms |
492 KB |
Output is correct |
3 |
Correct |
112 ms |
4776 KB |
Output is correct |
4 |
Correct |
112 ms |
4772 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
492 KB |
Output is correct |
2 |
Correct |
6 ms |
492 KB |
Output is correct |
3 |
Correct |
593 ms |
36812 KB |
Output is correct |
4 |
Correct |
542 ms |
34792 KB |
Output is correct |
5 |
Correct |
741 ms |
38980 KB |
Output is correct |
6 |
Correct |
786 ms |
37852 KB |
Output is correct |
7 |
Correct |
112 ms |
4776 KB |
Output is correct |
8 |
Correct |
112 ms |
4772 KB |
Output is correct |
9 |
Correct |
1102 ms |
41540 KB |
Output is correct |
10 |
Correct |
1088 ms |
41528 KB |
Output is correct |
11 |
Correct |
1086 ms |
41420 KB |
Output is correct |