#include <bits/stdc++.h>
using namespace std ;
long long t[10000001];
void push(int v, int vl, int vr) {
}
void update(int l, int r, int x, int v, int vl, int vr) {
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
int n;
cin >> n;
long long a[n];
for (int i = 0; i < n; i++) {
cin >> a[i];
}
sort(a, a + n);
if (n <= 4000) {
long long x = 0;
for (int i = 0; i < n; i++) {
for (int j = 0; j <= i; j++) {
x ^= (a[i] + a[j]);
}
}
cout << x << '\n';
} else if (*max_element(a, a + n) <= 4000) {
int N = *max_element(a, a + n);
vector<int> cnt(N + 1, 0);
for (int i = 0; i < n; i++) cnt[a[i]]++;
long long x = 0;
for (int i = 0; i <= N; i++) {
if ((cnt[i] * (cnt[i] - 1) / 2 + cnt[i]) & 1)
x ^= (i + i);
if (cnt[i] & 1) {
for (int j = 0; j < i; j++) {
if (cnt[j] & 1)
x ^= (i + j);
}
}
}
cout << x << '\n';
} else if (*max_element(a, a + n) <= 1000000) {
int N = *max_element(a, a + n);
vector<int> cnt(N + 1, 0);
for (int i = 0; i < n; i++) cnt[a[i]]++;
long long x = 0;
for (int i = 0; i <= N; i++) {
if ((cnt[i] * (cnt[i] - 1) / 2 + cnt[i]) & 1)
x ^= (i + i);
}
vector<int> v;
for (int i = 0; i <= N; i++) {
if (cnt[i] & 1) v.push_back(i);
}
for (int i = 0; i < v.size(); i++) {
for (int j = 0; j < i; j++)
x ^= (v[i] + v[j]);
}
cout << x << '\n';
}
return 0;
}
Compilation message
xorsum.cpp: In function 'int main()':
xorsum.cpp:61:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
61 | for (int i = 0; i < v.size(); i++) {
| ~~^~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
7 ms |
332 KB |
Output is correct |
2 |
Correct |
5 ms |
332 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
152 ms |
8136 KB |
Output is correct |
2 |
Correct |
118 ms |
7588 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
152 ms |
8136 KB |
Output is correct |
2 |
Correct |
118 ms |
7588 KB |
Output is correct |
3 |
Execution timed out |
1682 ms |
14144 KB |
Time limit exceeded |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
7 ms |
332 KB |
Output is correct |
2 |
Correct |
5 ms |
332 KB |
Output is correct |
3 |
Incorrect |
16 ms |
972 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
7 ms |
332 KB |
Output is correct |
2 |
Correct |
5 ms |
332 KB |
Output is correct |
3 |
Correct |
152 ms |
8136 KB |
Output is correct |
4 |
Correct |
118 ms |
7588 KB |
Output is correct |
5 |
Execution timed out |
1682 ms |
14144 KB |
Time limit exceeded |
6 |
Halted |
0 ms |
0 KB |
- |