Submission #1183580

#	Time	Username	Problem	Language	Result	Execution time	Memory
1183580		countless	Crayfish scrivener (IOI12_scrivener)	C++20	Compilation error	0 ms	0 KiB

scrivener

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;

const ll MOD = 998244353;
const ll INF = 1e18;
const ld EPS = 1e-12;

#define endl "\n"
#define sp <<" "<<
#define REP(i, a, b) for(ll i = a; i < b; i++)
#define dbg(x) cout << #x << " = " << x << endl
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define fast_io() ios_base::sync_with_stdio(false); cin.tie(NULL)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) ((ll)(x).size())

struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        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 Key, typename Value>
using hash_map = unordered_map<Key, Value, custom_hash>;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
// uniform_int_distribution<int>(a, b)(rng);
// shuffle(all(a), rng);

const int MAXN = 1e6+5;
const int LOGN = 22;
vector<int> state;
int depth[MAXN];
int up[MAXN][LOGN];
int ind = 0;
char ch[MAXN];

void Init() {
    state.push_back(0);
    depth[0] = -1;
    ch[0] = ''; // shouldn't happen
}

void TypeLetter(char L) {
    int curr = state.back();
    ind++;
    state.push_back(ind);
    ch[ind] = L;
    depth[ind] = depth[curr] + 1;
    up[ind][0] = curr;

    // bin lift
    for (int i = 1; i < LOGN; i++) {
        up[ind][i] = up[ up[ind][i-1] ][i-1];
    }
}

void UndoCommands(int U) {
    state.push_back(state[state.size()-U-1]);
}

char GetLetter(int P) {
    int curr = state.back();
    int lift = depth[curr] - P;

    // bin lift
    for (int i = LOGN-1; i >= 0; i--) {
        if (lift && (1 << i))
            curr = up[curr][i];
    }

    return ch[curr];
}

// int main() {
//     Init();

//     int n; cin >> n;
//     char command;
//     REP(i, 0, n) {
//         cin >> command;

//         if (command == 'T') {
//             char c; cin >> c;
//             TypeLetter(c);
//         }
        
//         else if (command == 'U') {
//             int x; cin >> x;
//             UndoCommands(x);
//         }

//         else {
//             int x; cin >> x;
//             cout << GetLetter(x) << endl;
//         }
//     }
// }

Compilation message (stderr)

scrivener.cpp:57:13: error: empty character constant
   57 |     ch[0] = ''; // shouldn't happen
      |             ^~