oj.uz

Submission #883632

# Submission time Handle Problem Language Result Execution time Memory
883632 2023-12-05T14:32:11 Z Requiem XOR (IZhO12_xor) C++17
0 / 100
 2000 ms 109876 KB 
#include<bits/stdc++.h>
#define pb push_back
#define fast ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
#define MOD 1000000007
#define INF 2147483646
#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 = 1001;
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()};
    int bitpre, bit, it, p, pw2;
    void addnum(int x){
        p = 1;
        for(it=30;it>=0;it--){
            bit = (x>>it)&1;
            if (Trie[p].child[bit] == 0){
                Trie[p].child[bit] = Trie.size();
                Trie.pb(TrieNode());
            }
            p = Trie[p].child[bit];
        }
    }
    inline bool check(int pre,int x){
        p = 1;
        for(it=30;it>=0;it--){
            bitpre = (pre>>it)&1;
            pw2 = (1LL<<it);
            if (Trie[p].child[!bitpre]){
                if (x >= pw2 * 2) return false;
                x -= pw2;
                if (x < 0) return true;

                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<=2002;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:90:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   90 | main()
      | ^~~~
xor.cpp: In function 'int main()':
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".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
xor.cpp:95:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   95 |         freopen(TASKNAME".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3420 KB Output is correct
2 Correct 2 ms 3420 KB Output is correct
3 Correct 1 ms 3420 KB Output is correct
4 Correct 3 ms 3676 KB Output is correct
5 Correct 87 ms 8348 KB Output is correct
6 Correct 152 ms 9916 KB Output is correct
7 Correct 170 ms 10336 KB Output is correct
8 Correct 201 ms 10844 KB Output is correct
9 Correct 1228 ms 92188 KB Output is correct
10 Correct 1195 ms 93872 KB Output is correct
11 Correct 1238 ms 87500 KB Output is correct
12 Correct 1225 ms 90716 KB Output is correct
13 Correct 1227 ms 95520 KB Output is correct
14 Correct 1183 ms 90628 KB Output is correct
15 Correct 1214 ms 92884 KB Output is correct
16 Correct 1255 ms 90568 KB Output is correct
17 Execution timed out 2051 ms 109876 KB Time limit exceeded
18 Halted 0 ms 0 KB -