oj.uz

Submission #883634

# Submission time Handle Problem Language Result Execution time Memory
883634 2023-12-05T14:42:32 Z Requiem XOR (IZhO12_xor) C++17
0 / 100
 2000 ms 127280 KB 
#include<iostream>
#include<algorithm>
#include<cstring>
#include<vector>
#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 endl "\n"
#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 = 501;
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=29;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=29;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;
    int g1 = getminblock(node<<1,l,mid,u,v,pre);
    if (g1 != INF) return g1;
    else return 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:87:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   87 | main()
      | ^~~~
xor.cpp: In function 'int main()':
xor.cpp:91:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |         freopen(TASKNAME".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
xor.cpp:92:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   92 |         freopen(TASKNAME".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2904 KB Output is correct
2 Correct 1 ms 2908 KB Output is correct
3 Correct 1 ms 2908 KB Output is correct
4 Correct 2 ms 3164 KB Output is correct
5 Correct 85 ms 9204 KB Output is correct
6 Correct 152 ms 11108 KB Output is correct
7 Correct 172 ms 11416 KB Output is correct
8 Correct 205 ms 12732 KB Output is correct
9 Correct 1250 ms 108136 KB Output is correct
10 Correct 1234 ms 107088 KB Output is correct
11 Correct 1268 ms 107064 KB Output is correct
12 Correct 1281 ms 107596 KB Output is correct
13 Correct 1231 ms 107948 KB Output is correct
14 Correct 1217 ms 105828 KB Output is correct
15 Correct 1251 ms 108488 KB Output is correct
16 Correct 1248 ms 106020 KB Output is correct
17 Execution timed out 2064 ms 127280 KB Time limit exceeded
18 Halted 0 ms 0 KB -