oj.uz

Submission #883621

# Submission time Handle Problem Language Result Execution time Memory
883621 2023-12-05T14:20:22 Z Requiem XOR (IZhO12_xor) C++17
0 / 100
 2000 ms 254488 KB 
#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define fast ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
#define MOD 1000000007
#define INF 1e18
#define fi first
#define se second
#define endl "\n"
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define FORD(i,a,b) for(int i=a;i>=b;i--)
#define sz(a) ((int)(a).size())
#define pi 3.14159265359
#define TASKNAME "Xor"
template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; }
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; }
using namespace std;
typedef pair<int,int> ii;
typedef pair<int,ii> iii;
typedef vector<int> vi;
const int MAXN = 250009;
const int block = 703;
int n,k;
int a[MAXN],prexor[MAXN];
struct TrieNode{
    int child[2];
    TrieNode(){
       memset(child,0,sizeof(child));
    }
};
struct Trie{
    vector<TrieNode> Trie = {TrieNode(),TrieNode()};
    void addnum(int x){
        int p = 1;
        for(int i=30;i>=0;i--){
            int bit = (x>>i)&1;
            if (Trie[p].child[bit] == 0){
                Trie[p].child[bit] = Trie.size();
                Trie.pb(TrieNode());
            }
            p = Trie[p].child[bit];
        }
    }
    bool check(int pre,int x){
        int p = 1, mx = 0;
        for(int i=30;i>=0;i--){
            int bitpre = (pre>>i)&1;
            int pw2 = (1LL<<i);
            if (Trie[p].child[!bitpre]){
                if (x >= pw2 * 2) return false;
                x -= pw2;

                p = Trie[p].child[!bitpre];
            }
            else{
                p = Trie[p].child[bitpre];
            }
        }
        return (x <= 0);
    }
};
Trie TrieBlock[2003];
int starting[MAXN],ending[MAXN];
int maxlen, minpos,x;
void update(int node,int l,int r,int pos,int pre){
    TrieBlock[node].addnum(pre);
    if (l==r) return;
    int mid = (l+r)>>1;
    if (pos <= mid) update(node<<1,l,mid,pos,pre);
    else update(node<<1|1,mid+1,r,pos,pre);
}
int getminblock(int node,int l,int r,int u,int v,int pre){
    int mid = (l+r)>>1;
    if (l>=u and r<=v){
        if (l==r) return l;
        if (TrieBlock[node<<1].check(pre,x)){
            return getminblock(node<<1,l,mid,u,v,pre);
        }
        else if (TrieBlock[node<<1|1].check(pre,x)){
            return getminblock(node<<1|1,mid+1,r,u,v,pre);
        }
        else return INF;
    }
    if (l>v or r<u) return INF;
    return min(getminblock(node<<1,l,mid,u,v,pre),
               getminblock(node<<1|1,mid+1,r,u,v,pre));

}
main()
{
    fast;
   if (fopen(TASKNAME".inp","r")){
        freopen(TASKNAME".inp","r",stdin);
        freopen(TASKNAME".out","w",stdout);
   }
   cin>>n>>x;
   for(int i=1;i<=n;i++){
       cin>>a[i];
       prexor[i] = prexor[i-1] ^ a[i];
   }
   for(int i=0;i<n;i++){
       starting[i/block] = (starting[i/block] == -1) ? i : starting[i/block];
       ending[i/block] = i;
   }
   for(int i=0;i<=2000;i++){
       TrieBlock[i].addnum(0);
   }
   int MXBLOCK = (n-1) / block;
   int minblock = 0, idblock;
   for(int i=0;i<=n;i++){
       idblock = i / block;
       minblock = getminblock(1,0,MXBLOCK,0,idblock,prexor[i]);
       if (minblock != INF){
           for(int j=starting[minblock];j<=ending[minblock];j++){
                if ((prexor[i] ^ prexor[j]) >= x){
                   if (maximize(maxlen,i - j)){
                       minpos = j + 1;
                   }
                   else if (maxlen == i - j){
                       minimize(minpos, j + 1);
                   }
               }
           }
       }
       update(1,0,MXBLOCK,idblock,prexor[i]);
   }
   cout<<minpos<<' '<<maxlen<<endl;
}

Compilation message

xor.cpp: In member function 'bool Trie::check(long long int, long long int)':
xor.cpp:45:20: warning: unused variable 'mx' [-Wunused-variable]
   45 |         int p = 1, mx = 0;
      |                    ^~
xor.cpp: At global scope:
xor.cpp:89:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   89 | main()
      | ^~~~
xor.cpp: In function 'int main()':
xor.cpp:93:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   93 |         freopen(TASKNAME".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
xor.cpp:94:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |         freopen(TASKNAME".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 6492 KB Output is correct
2 Correct 2 ms 6492 KB Output is correct
3 Correct 2 ms 6492 KB Output is correct
4 Correct 4 ms 7256 KB Output is correct
5 Correct 104 ms 17088 KB Output is correct
6 Correct 137 ms 20916 KB Output is correct
7 Correct 151 ms 21412 KB Output is correct
8 Correct 159 ms 23844 KB Output is correct
9 Correct 1734 ms 210644 KB Output is correct
10 Correct 1716 ms 216880 KB Output is correct
11 Correct 1722 ms 208000 KB Output is correct
12 Correct 1692 ms 208516 KB Output is correct
13 Correct 1725 ms 205996 KB Output is correct
14 Correct 1693 ms 209164 KB Output is correct
15 Correct 1718 ms 207960 KB Output is correct
16 Correct 1714 ms 210532 KB Output is correct
17 Execution timed out 2048 ms 254488 KB Time limit exceeded
18 Halted 0 ms 0 KB -