제출 #1135434

#제출 시각아이디문제언어결과실행 시간메모리
1135434shoeibXOR (IZhO12_xor)C++20
100 / 100
153 ms86652 KiB
// Author: Muhammed Khaled Shoeib #include <bits/stdc++.h> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> using namespace __gnu_pbds; using namespace std; //.................................................... // struct to speed-up the unordered data structures like map/set. struct hash_function // unordered + modified hash >> ordered { static uint64_t splitmix64(uint64_t x) { x += 0x9e3779b97f4a7c15; x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9; x = (x ^ (x >> 27)) * 0x94d049bb133111eb; return x ^ (x >> 31); } size_t operator()(uint64_t x) const { static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count(); return splitmix64(x + FIXED_RANDOM); } }; //.................................................... template < typename T, typename Compare = less < T > > // O(logn) using ordered_set = tree < T, null_type, Compare, rb_tree_tag, tree_order_statistics_node_update>; // less_equal: asc. not_unique, st.order_of_key(k) --> no. of items < k, less: unique // greater_equal: desc. not_unique, st.order_of_key(k) --> no. of items > k, greater: unique // *st.find_by_order(k) --> st[k] (Zero-indexed) // less_equal (u can't erase here!) == multi-set template < typename T > using maxpq = priority_queue < T >; template < typename T > using minpq = priority_queue < T, vector< T >, greater< T > >; //.................................................... #define boost ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0) #define precision(a) cout << fixed << setprecision(a) #define alo cout << "alooooooooooo!" << endl #define YES cout << "YES" << endl #define Yes cout << "Yes" << endl #define yes cout << "yes" << endl #define NO cout << "NO" << endl #define No cout << "No" << endl #define no cout << "no" << endl #define ne cout << -1 << endl #define endl "\n" #define mem(mat, val) memset(mat, val, sizeof(mat)) #define ones(x) __builtin_popcountll(x) #define msb(x) 63ll - __builtin_clzll(x) #define lsb(x) __builtin_ffsll(x) - 1ll //.................................................... #define all(x) x.begin(), x.end() #define rall(x) x.rbegin(),x.rend() #define ceil_(a, b) (((ll)(a) + (ll)(b - 1)) / (ll)(b)) // up #define floor_(a, b) (a / b) // down #define round_(a, b) ((a + (b / 2ll)) / b) // nearest //.................................................... // using ll = int; // take care of this shit! using ll = long long; using i64 = long long; using i32 = int; using ld = long double; using ull = unsigned long long; using lli = long long int; //...................................................... ll gcd_(ll x, ll y) { return y ? gcd_(y, x % y) : x; } // O(log(min(x, y))) ll lcm_(ll a, ll b) { ll g = gcd_(a, b); return (a * b) / g; } //mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); //#define getrand(l, r) uniform_int_distribution<long long>(l, r)(rng) //...................................................... int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1}; int dx_diag[4] = { 1, 1, -1, -1 }, dy_diag[4] = { 1, -1, -1, 1 }; int dx_all[8] = {-1, -1, -1, 0, 1, 1, 1, 0}, dy_all[8] = {-1, 0, 1, 1, 1, 0, -1, -1}; int dx_knight[8] = {2, 2, 1, 1, -2, -2, -1, -1}, dy_knight[8] = {1, -1, 2, -2, 1, -1, 2, -2}; const ld pi = 3.141592653589793238462643383279; // acos(-1) const ld eps = 1e-9; const ll inf = (ll)INT32_MAX; // 2e9 const ll oo = (ll)1e15; // 1e15 (may cause OF in DP, Binary Search, ...) const ll OO = (ll)INT64_MAX; // 9e18 const ll mod = (ll)1e9 + 7; // 1e9 + 7, 998244353 //..................................................... // string(len, char); /* * think twice, code once. * think of different approaches to tackle a problem, write them down. * think of different views of the problem, don't look from only one side. * don't get stuck in one approach/problem. * common mistakes: line 48, overflow (sum of many numbers), corner cases, over/under count, infinite loops, * TLE, MLE (int instead of ll, using memset, Recursive DP, ...), RTE (out of bounds indexing), .... */ ///____________________________________________ Shoeib __________________________________________________________ /* Binary Trie */ // usefull when dealing with a lot of binary numbers (we can move over all numbers in the same time). // efficient insertion, deletion, counting, search for specific property (<, >, =, min, max, xor, ...), ... // start from msb -to-> lsb. // the time complexity of all operations is O(n), where n is the number of bits in the number being processed. // if MLE --> remove useless variables. // try to draw on a paper, and see information stored in each node. // .................... const ll mx_sz = 2, Bits = 30; // .................... struct Binary_Trie { struct Node { Node *ch[mx_sz]; ll freq, idx; Node() { mem(ch, 0); freq = 0; idx = oo; } }; Node *root; Binary_Trie() { root = new Node(); } void insert(const ll &x, const ll &i) // insert a new number { Node *curr = root; for(ll bit = Bits; bit >= 0; bit--) { ll idx = ((x >> bit) & 1ll); if(!curr->ch[idx]) curr->ch[idx] = new Node(); curr = curr->ch[idx]; curr->freq++; curr->idx = min(curr->idx, i); } } // more methods ... ll query(const ll &x, const ll &k) // return min index, have xor >= k { Node *curr = root; ll ret = 2*oo; for(ll bit = Bits; bit >= 0; bit--) { if(((x >> bit) & 1ll)) // 1 { if(((k >> bit) & 1ll)) // 1 { // can't take ones, go to zeros if(curr->ch[0]) { if(bit == 0) ret = min(ret, curr->ch[0]->idx); curr = curr->ch[0]; } else return ret; } else // 0 { // take all zeros, go to ones if(curr->ch[0]) ret = min(ret, curr->ch[0]->idx); if(curr->ch[1]) { if(bit == 0) ret = min(ret, curr->ch[1]->idx); curr = curr->ch[1]; } else return ret; } } else // 0 { if(((k >> bit) & 1ll)) // 1 { // can't take zeros, go to ones if(curr->ch[1]) { if(bit == 0) ret = min(ret, curr->ch[1]->idx); curr = curr->ch[1]; } else return ret; } else // 0 { // take all ones, go to zeros if(curr->ch[1]) ret = min(ret, curr->ch[1]->idx); if(curr->ch[0]) { if(bit == 0) ret = min(ret, curr->ch[0]->idx); curr = curr->ch[0]; } else return ret; } } } return ret; } }; // .................... void solve() { ll n, k; cin >> n >> k; vector < ll > a(n + 1); a[0] = 0; for(ll i = 1; i <= n; i++) cin >> a[i]; Binary_Trie trie = Binary_Trie(); ll xor_sm = 0, l = 0, len = 0; for(ll i = 0; i <= n; i++) { xor_sm ^= a[i]; ll ret = trie.query(xor_sm, k); if(ret != oo) { ret++; if(i - ret + 1 > len) { l = ret; len = i - ret + 1; } } trie.insert(xor_sm, i); } cout << l << ' ' << len << endl; return; } signed main() { boost; // freopen("assessment.in", "r", stdin); // freopen("output.txt", "w", stdout); // precision(15); i32 _ = 1; //cin >> _; // cout.flush(); while(_--) solve(); return 0; }
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