Submission #908925

#	Time	Username	Problem	Language	Result	Execution time	Memory
908925		borademirtas	XOR Sum (info1cup17_xorsum)	C++17	0 / 100	1629 ms	12880 KiB

xorsum

#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#pragma GCC optimize("O3,unroll-loops")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
#define ll long long
#define  vll vector<ll>
#define pb push_back
#define vp vector<pll>
#define tc ll t; cin >> t; for(ll i = 0; i < t; i++){solve(i, t);}
#define tc1 solve(1, 1);
#define mpvll map<ll, vll>
#define vfast vll a(n); for (ll i = 0; i < n; i++) { cin >> a[i]; }
#define mpll map<ll,ll>
#define pll pair<ll,ll>
#define vll2 vector<vector<ll>> dp(n, vector<ll>(m));b
#define FIXED(A) cout << fixed; cout.precision(20); cout << A << "\n";
#define mp(A, B) make_pair(A, B)
#define all(x) (x).begin(), (x).end()
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define sz(x) (int)(x).size()
#define big __int128
#define F first
#define S second
#define ckmin(a,b) a = min(a,b)
#define ckmax(a,b) a = max(a,b)
template <typename num_t>
using indexed_set = tree<num_t, null_type, less<num_t>, rb_tree_tag, tree_order_statistics_node_update>;
void setIO(string name) {freopen((name+".in").c_str(),"r",stdin);freopen((name+".out").c_str(),"w",stdout);}
ll rd(ll a, ll b){return (a+b-1) / b;}
ll isqrt(ll x){ll ans = 0; for(ll k = 1LL << 30; k != 0; k /= 2){if ((ans + k) * (ans + k) <= x) {ans += k;} } return ans;   }
vll prime(ll x){ll n = x; vll ans; while (n % 2 == 0) {ans.pb(2);n = n/2;} for (int i = 3; i <= sqrt(n); i = i + 2) {while (n % i == 0){ans.pb(i);n = n/i;}}if (n > 2){ans.pb(n);} return ans;}
ll binpow(ll a, ll b, ll m) { a %= m; ll res = 1; while (b > 0) { if (b & 1){res = res * a % m;}a = a * a % m; b >>= 1;} return res;}
ll lg2(ll n){ll cnt=0;while(n){cnt++;n/=2;}return cnt;}



void solve(ll TC, ll TC2) {

    ll n; cin >> n;
    vll a(n); for(ll i = 0; i < n; i++){cin >> a[i];}
    ll ans = 0;
    for(ll bit =30; bit >= 0; bit--){
        ll pw = 1LL<<bit;
        for(auto &x: a){x%=pw*2;}
        sort(all(a));
        ll cnt = 0;
        for(ll i = 0; i < n; i++){
            ll lb = lower_bound(all(a), pw-a[i]) - a.begin();
            ll ub = lower_bound(all(a), 2*pw-a[i]) - a.begin();
            //cout << ub << ' ' << lb << " " << a[i] << '\n';
            cnt+=ub-lb;
            lb = lower_bound(all(a), pw*3-a[i]) - a.begin();
            //cout << lb << '\n';
            cnt += n-lb;
            if(a[i]*2>=pw&&a[i]*2<pw*2){cnt--;}
            if(a[i]*2>=pw*3){cnt--;}
        }
        //cout << '\n';
        cnt/=2;
        if(cnt&1){ans+=pw;}
    }
    cout << ans << '\n';
}




int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);
    tc1
}

Compilation message (stderr)

xorsum.cpp: In function 'void setIO(std::string)':
xorsum.cpp:31:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 | void setIO(string name) {freopen((name+".in").c_str(),"r",stdin);freopen((name+".out").c_str(),"w",stdout);}
      |                          ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
xorsum.cpp:31:73: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 | void setIO(string name) {freopen((name+".in").c_str(),"r",stdin);freopen((name+".out").c_str(),"w",stdout);}
      |                                                                  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 11
• Subtask 3: 0 / 21
• Subtask 4: 0 / 38
• Subtask 5: 0 / 23