| # | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
|---|---|---|---|---|---|---|---|
| 674005 | 2022-12-22T14:22:15 Z | QwertyPi | Easter Eggs (info1cup17_eastereggs) | C++14 | 0 ms | 0 KB |
#include <bits/stdc++.h>
#define int long long
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
using namespace std;
const int N = 1e6 + 11;
int a[N], b0[N], b0n, b1[N], b1n;
int d[N], d1[N], d2[N];
int32_t main(){
cin.tie(0); cout.tie(0)->sync_with_stdio(false);
int n; cin >> n;
for(int i = 0; i < n; i++){
cin >> a[i];
}
int ans = 0;
for(int s = 29; s >= 19; s--){
int c = 0;
b0n = b1n = 0;
for(int j = 0; j < n; j++){
if(a[j] & (1 << s)) b1[b1n++] = a[j] % (1 << s);
else b0[b0n++] = a[j] % (1 << s);
}
sort(b0, b0 + b0n); sort(b1, b1 + b1n);
int r = b0n;
for(int l = 0; l < b0n; l++){
r = max(r, l + 1);
while(r - 1 > l && b0[l] + b0[r - 1] >= (1 << s)) r--;
c += b0n - r;
}
r = b1n;
for(int l = 0; l < b1n; l++){
r = max(r, l + 1);
while(r - 1 > l && b1[l] + b1[r - 1] >= (1 << s)) r--;
c += b1n - r;
}
r = b1n;
for(int l = 0; l < b0n; l++){
while(r > 0 && b0[l] + b1[r - 1] >= (1 << s)) r--;
c += b1n - r;
}
c += b0n * b1n;
ans ^= (1 << s) * (c % 2);
}
for(int j = 0; j < n; j++) d[a[j] % (1 << 19)]++;
for(int s = 18; s >= 0; s--){
int c = 0;
b0n = accumulate(d, d + (1 << s), 0LL);
b1n = accumulate(d + (1 << s), d + (1 << s + 1), 0LL);
int tot = 0;
for(int i = 1; i < (1 << s) / 2; i++){
tot += d[(1 << s) - i];
c += tot * d[i];
}
tot = 0;
for(int i = (1 << s) / 2; i < (1 << s); i++){
tot += d[i];
}
c += tot * (tot - 1) / 2;
tot = 0;
for(int i = 1; i < (1 << s) / 2; i++){
tot += d[(1 << s) + (1 << s) - i];
c += tot * d[(1 << s) + i];
}
tot = 0;
for(int i = (1 << s) / 2; i < (1 << s); i++){
tot += d[(1 << s) + i];
}
c += tot * (tot - 1) / 2;
tot = 0;
for(int i = 1; i < (1 << s); i++){
tot += d[(1 << s) + (1 << s) - i];
c += tot * d[i];
}
c += b0n * b1n;
if(s){
for(int i = 0; i < (1 << s); i++) d[i] += d[i + (1 << s)];
}
ans ^= (1 << s) * (c % 2);
}
for(int i = 0; i < n; i++){
ans ^= (a[i] * 2);
}
cout << ans << endl;
}