제출 #930561

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
930561		Baizho	XOR Sum (info1cup17_xorsum)	C++14	45 / 100	1636 ms	16088 KiB

xorsum

#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
  
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
 
// #pragma GCC optimize("Ofast,unroll-loops,fast-math")
// #pragma GCC target("popcnt")
 
 
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll,ll> pll;
 
#define sz size()
#define ff first
#define ss second
#define all(a) a.begin(),a.end()
#define pb push_back
 
const int mod = ll(1e9)+7; //(b + (a%b)) % b (to mod -1%(10^9+7) correctly in c++ its -1 but its suppose to be 10^9+6
const ll MOD = 998244353;  // (a%mod)*(binpow(b,mod-2,mod) = (a/b)%mod
const int N = ll(4e5)+100;
const int M = ll(2e5) + 100;
const long long inf = 5e18;
const long double eps = 1e-15L;
 
ll lcm(ll a, ll b) { return (a / __gcd(a,b))*b; }
 
ll binpow(ll a, ll b, ll m) { ll res=1; a %= m; while(b>0){ if(b&1)res=(res * a) % m; a=(a * a) % m; b/=2; } return res%m;}
 
void Freopen(string Key){ freopen((Key+".in").c_str(), "r", stdin); freopen((Key+".out").c_str(), "w", stdout); }

#define int ll
 
void Baizho() {
	int n; cin>>n;
	int a[n + 1], b[n + 1];
	for(int i = 1; i <= n; i ++) cin>>a[i];
	int ans = 0;
	for(int k = 0; k < 29; k ++) {
		for(int i = 1; i <= n; i ++) b[i] = a[i] % (1ll << (k + 1));
		sort(b + 1, b + n + 1);
		int cnt = 0, p1 = n + 1, p2 = n, p3 = n + 1, p4 = n;
		for(int i = 1; i <= n; i ++) {
			p1 = max(p1, i + 1);
			while(p1 - 1 >= i && b[i] + b[p1 - 1] >= (1 << k)) p1 --;
			p2 = max(p2, i);
			while(p2 >= i && b[i] + b[p2] >= (1ll << (k + 1))) p2 --;
			p3 = max(p3, i + 1);
			while(p3 - 1 >= i && b[i] + b[p3 - 1] >= (1ll << k) + (1ll << (k + 1))) p3 --;
			p4 = max(p4, i);
			while(p4 >= i && b[i] + b[p4] >= (1ll << (k + 2))) p4 --;
//			cout<<p1<<" "<<p2<<" "<<p3<<" "<<p4<<" "<<k<<" "<<i<<endl;
			cnt += max(p2 - p1 + 1, 0ll);
			cnt += max(p4 - p3 + 1, 0ll);
		}
		if(cnt & 1) {
			ans ^= (1ll << k);
//			cout<<k<<"\n";
		}
	}
	cout<<ans<<"\n";
}
 
signed main() {		
// 	Freopen("nondec");
    ios_base::sync_with_stdio(false);   
    cin.tie(0);cout.tie(0); 
//   	precalc();
   	
    int ttt = 1;
//    cin>>ttt;
 
    for(int i=1; i<=ttt; i++) {Baizho(); }
}

컴파일 시 표준 에러 (stderr) 메시지

xorsum.cpp: In function 'void Freopen(std::string)':
xorsum.cpp:35:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 | void Freopen(string Key){ freopen((Key+".in").c_str(), "r", stdin); freopen((Key+".out").c_str(), "w", stdout); }
      |                           ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
xorsum.cpp:35:76: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 | void Freopen(string Key){ freopen((Key+".in").c_str(), "r", stdin); freopen((Key+".out").c_str(), "w", stdout); }
      |                                                                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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