Submission #674005

#	Time	Username	Problem	Language	Result	Execution time	Memory
674005		QwertyPi	Easter Eggs (info1cup17_eastereggs)	C++14	Compilation error	0 ms	0 KiB

eastereggs

#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;
}

Compilation message (stderr)

eastereggs.cpp: In function 'int32_t main()':
eastereggs.cpp:53:46: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   53 |   b1n = accumulate(d + (1 << s), d + (1 << s + 1), 0LL);
      |                                            ~~^~~
/usr/bin/ld: /tmp/ccaVKG8w.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cchPWETx.o:eastereggs.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccaVKG8w.o: in function `main':
grader.cpp:(.text.startup+0x1e6): undefined reference to `findEgg(int, std::vector<std::pair<int, int>, std::allocator<std::pair<int, int> > >)'
collect2: error: ld returned 1 exit status