Submission #1104074

#	Time	Username	Problem	Language	Result	Execution time	Memory
1104074		vjudge1	XOR (IZhO12_xor)	C++17	0 / 100	1 ms	336 KiB

xor

//      بسم الله الرحمن الرحيم
//      All praise is due to ALLAH alone
#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 endl '\n'
#define exit return 0
#define ll long long int
#define ull unsigned long long int
#define read freopen ("input.txt","r",stdin);
#define write freopen ("output.txt","w",stdout);
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define print_vec(vec) for(int i=0;i<vec.size();i++){cout<<vec[i]<<' ';}cout<<"\n";
#define print_set(st) for(auto it=st.begin();it!=st.end();it++){cout<<*it<<' ';}cout<<"\n";
typedef tree<ll, null_type, less_equal<ll>, rb_tree_tag, tree_order_statistics_node_update>ordered_set;
#define print_pair(vec) for(int i=0;i<vec.size();i++)cout<<vec[i].first<<' '<<vec[i].second<<endl;
#define dbg(num) cerr<< "Line "<<__LINE__ <<": "<< #num <<" = "<<(num)<<endl
// find_by_order() and order_of_key()
// k-th sorted element and lower_bound
//priority_queue <int, vector<int>, greater<int> > pq; **non_decreasing
//int dx[] = { -2, -2, -1, -1,  1,  1,  2,  2};
//int dy[] = { -1,  1, -2,  2, -2,  2, -1,  1};
ll lcm (ll a, ll b) {return a * (b / __gcd(a, b));}
int dx[] = { -1, 0, +1, 0};
int dy[] = {0, +1, 0, -1};
#define sz 200001
#define mod 1000000007
void solve()
{
	ll n, x;
	cin >> n >> x;
	ll arr[n + 1];
	map<ll, ll>prefix;
	vector<ll>maxi(n + 1, 0);
	vector<int>index(n + 1, 1e9);
	ll curr = 0;
	int ans = 0, start;
	for (int i = 1; i <= n; i++)
	{
		cin >> arr[i];
		curr ^= arr[i];
		ll need = curr ^ x;
		if (prefix[need])
		{
			int id = prefix[need];
			if (maxi[id] > need)
			{
				id = index[id];
			}
			int len = i - id + 1;
			if (len > ans)
				ans = len, start = id;
		}
		if (prefix[curr] == 0)
			prefix[curr] = i;
		if (maxi[i - 1] > curr)
			maxi[i] = maxi[i - 1], index[i] = index[i - 1];
		else maxi[i] = curr, index[i] = i;
	}
	cout << start << ' ' << ans << endl;
}
int main()
{
	fast;
	int tc = 1;
	//cin >> tc;
	while (tc--)
		solve();
//.............................................. ٱلْحَمْدُ لِلَّٰ......................................
}

Compilation message (stderr)

xor.cpp: In function 'void solve()':
xor.cpp:62:19: warning: 'start' may be used uninitialized in this function [-Wmaybe-uninitialized]
   62 |  cout << start << ' ' << ans << endl;
      |                   ^~~

• Subtask 1: 0 / 100