oj.uz

Submission #674008

# Submission time Handle Problem Language Result Execution time Memory
674008 2022-12-22T14:34:33 Z QwertyPi XOR Sum (info1cup17_xorsum) C++14
100 / 100
 1095 ms 33440 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;
		if(s != 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;
		if(s != 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

xorsum.cpp: In function 'int32_t main()':
xorsum.cpp:53:46: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   53 |   b1n = accumulate(d + (1 << s), d + (1 << s + 1), 0LL);
      |                                            ~~^~~

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4436 KB Output is correct
2 Correct 6 ms 4436 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 750 ms 17912 KB Output is correct
2 Correct 682 ms 21196 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 750 ms 17912 KB Output is correct
2 Correct 682 ms 21196 KB Output is correct
3 Correct 1016 ms 30088 KB Output is correct
4 Correct 990 ms 29592 KB Output is correct

Subtask #4
38.0 / 38.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4436 KB Output is correct
2 Correct 6 ms 4436 KB Output is correct
3 Correct 102 ms 7116 KB Output is correct
4 Correct 103 ms 7148 KB Output is correct

Subtask #5
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4436 KB Output is correct
2 Correct 6 ms 4436 KB Output is correct
3 Correct 750 ms 17912 KB Output is correct
4 Correct 682 ms 21196 KB Output is correct
5 Correct 1016 ms 30088 KB Output is correct
6 Correct 990 ms 29592 KB Output is correct
7 Correct 102 ms 7116 KB Output is correct
8 Correct 103 ms 7148 KB Output is correct
9 Correct 1095 ms 33408 KB Output is correct
10 Correct 1086 ms 33440 KB Output is correct
11 Correct 1090 ms 33296 KB Output is correct