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Submission #391502

# Submission time Handle Problem Language Result Execution time Memory
391502 2021-04-19T02:56:58 Z warner1129 XOR Sum (info1cup17_xorsum) C++17
100 / 100
 548 ms 20420 KB 
#include <bits/stdc++.h>

using namespace std;

const int maxn = 1e6 + 5;

int arr[maxn], n;
int A[maxn], B[maxn], p1, p2;

int check() {
	int ret = 0;
	for (int i = 1; i <= n; i++)
		for (int j = i; j <= n; j++)
			ret ^= arr[i] + arr[j];
	return ret;
}

void solve() {
	cin >> n;
	for (int i = 1; i <= n; i++) cin >> arr[i];
	int ans = 0;
	for (int i = 0; i < 30; i++) {
		int R = (1<<i) - 1;
		p1 = p2 = 0;
		for (int j = 1; j <= n; j++)
			if ((arr[j]>>i)&1) B[++p2] = arr[j];
			else A[++p1] = arr[j];
		int ptr = p1 + 1;
		for (int j = 1; j <= p1; j++) {
			while (ptr > j && (A[j]&R) + (A[ptr-1]&R) >= (1<<i)) ptr--;
			if (ptr < j) ptr = j;
			if ((p1-ptr+1)&1) ans ^= (1<<i);
		}
		ptr = p2 + 1;
		for (int j = 1; j <= p2; j++) {
			while (ptr > j && (B[j]&R) + (B[ptr-1]&R) >= (1<<i)) ptr--;
			if (ptr < j) ptr = j;
			if ((p2-ptr+1)&1) ans ^= (1<<i);
		}
		ptr = p2;
		for (int j = 1; j <= p1; j++) {
			while (ptr && (A[j]&R)+(B[ptr]&R) >= (1<<i)) ptr--;
			if (ptr&1) ans ^= (1<<i);
		}
		for (int j = 1; j <= p1; j++) arr[j] = A[j];
		for (int j = 1; j <= p2; j++) arr[p1 + j] = B[j];
	}
	cout << ans << '\n';
}

signed main() {
	ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
	solve();
	return 0;
}

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 332 KB Output is correct
2 Correct 3 ms 332 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 308 ms 15672 KB Output is correct
2 Correct 271 ms 14528 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 308 ms 15672 KB Output is correct
2 Correct 271 ms 14528 KB Output is correct
3 Correct 400 ms 17760 KB Output is correct
4 Correct 372 ms 17188 KB Output is correct

Subtask #4
38.0 / 38.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 332 KB Output is correct
2 Correct 3 ms 332 KB Output is correct
3 Correct 60 ms 2232 KB Output is correct
4 Correct 61 ms 2304 KB Output is correct

Subtask #5
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 332 KB Output is correct
2 Correct 3 ms 332 KB Output is correct
3 Correct 308 ms 15672 KB Output is correct
4 Correct 271 ms 14528 KB Output is correct
5 Correct 400 ms 17760 KB Output is correct
6 Correct 372 ms 17188 KB Output is correct
7 Correct 60 ms 2232 KB Output is correct
8 Correct 61 ms 2304 KB Output is correct
9 Correct 540 ms 20412 KB Output is correct
10 Correct 546 ms 20368 KB Output is correct
11 Correct 548 ms 20420 KB Output is correct