Submission #479385

#	Time	Username	Problem	Language	Result	Execution time	Memory
479385		arwaeystoamneg	XOR Sum (info1cup17_xorsum)	C++17	45 / 100	1697 ms	8772 KiB

xorsum

// EXPLOSION!
#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
#include<unordered_set>
#include<unordered_map>
#include<chrono>

using namespace std;
typedef pair<int, int> pii;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pair<int, int>> vpi;
typedef vector<pair<ll, ll>> vpll;

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

#define pb push_back
#define mp make_pair
#define rsz resize
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define f first
#define s second
#define cont continue
//#define endl '\n'
//#define ednl '\n'
#define test int testc;cin>>testc;while(testc--)
#define pr(a, b) trav(x,a)cerr << x << b; cerr << endl;
#define message cout << "Hello World" << endl;
//const int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 }; // for every grid problem!!
const ll linf = 4000000000000000000LL;
const ll inf = 1000000007;//998244353    

void pv(vi a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vll a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vector<vi>a) {
	F0R(i, sz(a)) { cout << i << endl; pv(a[i]); cout << endl; }
}void pv(vector<vll>a) { F0R(i, sz(a)) { cout << i << endl; pv(a[i]); }cout << endl; }void pv(vector<string>a) { trav(x, a)cout << x << endl; cout << endl; }
void setIO(string s) {
	ios_base::sync_with_stdio(0); cin.tie(0);
#ifdef arwaeystoamneg
	if (sz(s))
	{
		freopen((s + ".in").c_str(), "r", stdin);
		if (s != "test1")
			freopen((s + ".out").c_str(), "w", stdout);
	}
#endif
}
int n;
vi a;
int main()
{
	setIO("test1");
	cin >> n;
	a.rsz(n); trav(x, a)cin >> x;
	int ans = 0;
	R0F(i, 30)
	{
		F0R(j, n)
		{
			if (a[j] & (1 << i + 1))a[j] ^= (1 << i + 1);
		}
		sort(all(a));
		int c = 0;
		int p1 = n - 1, p2 = n - 1;
		F0R(j, n)
		{
			while (p1 >= 0 && a[p1] >= (1 << i) - a[j])p1--;
			while (p2 >= 0 && a[p2] > (1 << i + 1) - a[j] - 1)p2--;
			c += min(p2, j) - min(p1, j);
		}
		F0R(j,n)
		{
			c += upper_bound(a.begin(), a.begin() + j + 1, (1 << i + 1) + (1 << i + 1) - a[j] - 1) - lower_bound(a.begin(), a.begin() + j + 1, (1 << i + 1) + (1 << i) - a[j]);
		}
		if (c & 1)ans ^= (1 << i);
	}
	cout << ans << endl;
}

Compilation message (stderr)

xorsum.cpp: In function 'int main()':
xorsum.cpp:67:23: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   67 |    if (a[j] & (1 << i + 1))a[j] ^= (1 << i + 1);
      |                     ~~^~~
xorsum.cpp:67:44: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   67 |    if (a[j] & (1 << i + 1))a[j] ^= (1 << i + 1);
      |                                          ~~^~~
xorsum.cpp:75:38: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   75 |    while (p2 >= 0 && a[p2] > (1 << i + 1) - a[j] - 1)p2--;
      |                                    ~~^~~
xorsum.cpp:80:59: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   80 |    c += upper_bound(a.begin(), a.begin() + j + 1, (1 << i + 1) + (1 << i + 1) - a[j] - 1) - lower_bound(a.begin(), a.begin() + j + 1, (1 << i + 1) + (1 << i) - a[j]);
      |                                                         ~~^~~
xorsum.cpp:80:74: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   80 |    c += upper_bound(a.begin(), a.begin() + j + 1, (1 << i + 1) + (1 << i + 1) - a[j] - 1) - lower_bound(a.begin(), a.begin() + j + 1, (1 << i + 1) + (1 << i) - a[j]);
      |                                                                        ~~^~~
xorsum.cpp:80:143: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   80 |    c += upper_bound(a.begin(), a.begin() + j + 1, (1 << i + 1) + (1 << i + 1) - a[j] - 1) - lower_bound(a.begin(), a.begin() + j + 1, (1 << i + 1) + (1 << i) - a[j]);
      |                                                                                                                                             ~~^~~

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