#include <bits/stdc++.h>
#define ll int
#define pb push_back
#define task "tests"
#define pll pair<ll, ll>
#define pi pair<ll, pll>
#define fi first
#define se second
using namespace std;
const ll mod = 1e15+7;
const ll N = 1e6+5;
const int base = 313;
ll n, m, t, k, T, ans, tong, c[N], a[N], b[N], h[N], dp[N], cnt, top[N], nchain[N], chain, par[N];
vector<pll> adj[N];
ll pw(ll k, ll n)
{
ll total = 1;
for(; n; n >>= 1)
{
if(n & 1)total = total * k % mod;
k = k * k % mod;
}
return total;
}
bool check(int j)
{
int l = 0, r = 0;
if(j)
{
b[0] = b[1] = 0;
for(int i = 0; i < n; i ++)
{
k = (a[i] >> (j-1)) & 1;
++b[k];
}
b[1] += b[0];
for(int i = n-1; i >= 0; i --)
{
k = (a[i] >> (j-1)) & 1;
c[--b[k]] = a[i];
}
for(int i = 0; i < n; i ++)a[i] = c[i];
}
int p = n-1;
for(int i = 0; i < n; i ++)l += ((a[i] >> j) & 1);
bool ok = 0;
for(int i = 0; i < n; i ++)
{
while(p >= i && (a[i] & ((1<<j)-1)) + (a[p] & ((1<<j)-1)) >= (1<<j))
{
r += ((a[p] >> j) & 1);
l -= ((a[p] >> j) & 1);
--p;
}
if((a[i] >> j) & 1)
{
if((r+p-i+1-l)&1)ok = !ok;
}
else
{
if((l+n-1-p-r)&1)ok = !ok;
}
l -= ((a[i] >> j) & 1);
if(p < i)
{
++p;
r -= ((a[p] >> j) & 1);
l += ((a[p] >> j) & 1);
}
}
return ok;
}
void sol()
{
cin >> n;
for(int i = 0; i < n; i ++)cin >> a[i];
for(int i = 0; i < 30; i ++)if(check(i))ans += (1<<i);
cout << ans;
}
int main()
{
if(fopen(task".in", "r"))
{
freopen(task".in", "r", stdin);
freopen(task".out", "w", stdout);
}
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int ntest = 1;
//cin >> ntest;
while(ntest -- > 0)
sol();
}
/*
5 1
0 1 2
0 2 3
1 3 5
2 4 6
1 1
4 3
*/
Compilation message
xorsum.cpp:11:20: warning: overflow in conversion from 'double' to 'int' changes value from '1.000000000000007e+15' to '2147483647' [-Woverflow]
11 | const ll mod = 1e15+7;
| ~~~~^~
xorsum.cpp: In function 'int main()':
xorsum.cpp:86:15: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
86 | freopen(task".in", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
xorsum.cpp:87:15: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
87 | freopen(task".out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
17 ms |
23876 KB |
Output is correct |
2 |
Correct |
17 ms |
23788 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
568 ms |
36240 KB |
Output is correct |
2 |
Correct |
570 ms |
35400 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
568 ms |
36240 KB |
Output is correct |
2 |
Correct |
570 ms |
35400 KB |
Output is correct |
3 |
Correct |
628 ms |
38368 KB |
Output is correct |
4 |
Correct |
612 ms |
37848 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
17 ms |
23876 KB |
Output is correct |
2 |
Correct |
17 ms |
23788 KB |
Output is correct |
3 |
Correct |
98 ms |
25572 KB |
Output is correct |
4 |
Correct |
93 ms |
25644 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
17 ms |
23876 KB |
Output is correct |
2 |
Correct |
17 ms |
23788 KB |
Output is correct |
3 |
Correct |
568 ms |
36240 KB |
Output is correct |
4 |
Correct |
570 ms |
35400 KB |
Output is correct |
5 |
Correct |
628 ms |
38368 KB |
Output is correct |
6 |
Correct |
612 ms |
37848 KB |
Output is correct |
7 |
Correct |
98 ms |
25572 KB |
Output is correct |
8 |
Correct |
93 ms |
25644 KB |
Output is correct |
9 |
Correct |
734 ms |
41060 KB |
Output is correct |
10 |
Correct |
748 ms |
40964 KB |
Output is correct |
11 |
Correct |
746 ms |
40964 KB |
Output is correct |