#include<bits/stdc++.h>
#define f first
#define s second
#define pii pair<int,int>
using namespace std;
const int mod = 1e9 + 7; // !
int t;
vector<int> x;
main(){
ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0);
int n;
cin >> n;
for(int i = 1; i <= n; i++) {
int a;
cin >> a;
x.push_back(a);
}
// vector<int> cn(30);
// for(int i = 0; i < n; i++) {
// for(int j = i; j < n; j++) {
// for(int k = 0; k < 30; k++)
// if((x[i] + x[j]) & (1 << k)) cn[k] += 1;
// }
// }
int ans = 0;
for(int i = 0; i <= 29; i++) {
vector<int> xn;
for(int j = 0; j < x.size(); j++) {
if(x[j] & (1 << i)) continue;
xn.push_back(x[j]);
}
for(int j = 0; j < x.size(); j++) {
if(x[j] & (1 << i)) xn.push_back(x[j]);
}
x = xn;
vector<int> v = {(1 << i) + (1 << (i + 1)), 1 << (i + 1), 1 << (i)};
vector<int> r(3);
r[0] = r[1] = r[2] = n;
int c = 0, M = (1ll << (i + 1)) - 1;
for(int j = 0; j < x.size(); j++) {
// cout << x[j] << " ";
for(int t = 0; t < 3; t++) {
while(r[t] > 0 && (x[r[t] - 1] & M) + (x[j] & M) >= v[t]) --r[t];
}
c += n - max(j, r[0]) + max(j, r[1]) - max(j, r[2]); // cout << c << endl;
}
// cout << i << " _ " << c << " " << cn[i] << endl;
if(c % 2) ans += 1 << i;
}
cout << ans;
}
Compilation message
xorsum.cpp:9:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
9 | main(){
| ^~~~
xorsum.cpp: In function 'int main()':
xorsum.cpp:28:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
28 | for(int j = 0; j < x.size(); j++) {
| ~~^~~~~~~~~~
xorsum.cpp:32:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
32 | for(int j = 0; j < x.size(); j++) {
| ~~^~~~~~~~~~
xorsum.cpp:40:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
40 | for(int j = 0; j < x.size(); j++) {
| ~~^~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
340 KB |
Output is correct |
2 |
Correct |
5 ms |
340 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
637 ms |
12304 KB |
Output is correct |
2 |
Correct |
532 ms |
11816 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
637 ms |
12304 KB |
Output is correct |
2 |
Correct |
532 ms |
11816 KB |
Output is correct |
3 |
Correct |
727 ms |
12424 KB |
Output is correct |
4 |
Correct |
688 ms |
12020 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
340 KB |
Output is correct |
2 |
Correct |
5 ms |
340 KB |
Output is correct |
3 |
Correct |
105 ms |
1644 KB |
Output is correct |
4 |
Correct |
106 ms |
1636 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
340 KB |
Output is correct |
2 |
Correct |
5 ms |
340 KB |
Output is correct |
3 |
Correct |
637 ms |
12304 KB |
Output is correct |
4 |
Correct |
532 ms |
11816 KB |
Output is correct |
5 |
Correct |
727 ms |
12424 KB |
Output is correct |
6 |
Correct |
688 ms |
12020 KB |
Output is correct |
7 |
Correct |
105 ms |
1644 KB |
Output is correct |
8 |
Correct |
106 ms |
1636 KB |
Output is correct |
9 |
Correct |
1004 ms |
12344 KB |
Output is correct |
10 |
Correct |
1002 ms |
12260 KB |
Output is correct |
11 |
Correct |
972 ms |
12484 KB |
Output is correct |