Submission #811017

#	Time	Username	Problem	Language	Result	Execution time	Memory
811017		TB_	Combo (IOI18_combo)	C++17	100 / 100	34 ms	600 KiB

combo

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

// #undef _GLIBCXX_DEBUG                // disable run-time bound checking, etc
// #pragma GCC optimize("Ofast,inline") // Ofast = O3,fast-math,allow-store-data-races,no-protect-parens
// #pragma GCC optimize ("unroll-loops")

// #pragma GCC target("bmi,bmi2,lzcnt,popcnt")                      // bit manipulation
// #pragma GCC target("movbe")                                      // byte swap
// #pragma GCC target("aes,pclmul,rdrnd")                           // encryption
// #pragma GCC target("avx,avx2,f16c,fma,sse3,ssse3,sse4.1,sse4.2") // SIMD

// #include <bits/extc++.h>
// using namespace __gnu_pbds;
// template<class T>using ordered_set = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
// template<class T>using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define ll long long
#define INF (ll)1e9+7
#define fo(i, n) for(int i=0;i<((ll)n);i++)
#define deb(x) cout << #x << " = " << x << endl;
#define deb2(x, y) cout << #x << " = " << x << ", " << #y << " = " << y << endl
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define LSOne(S) ((S) & (-S))
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
inline int readint(){ int v = 0; char c; while((c = getchar()) != EOF && c != ' ' && c != '\n'){ v *= 10; v += c - '0'; } return v; }
inline int readintsigned() { int v = 0; int sign = 1; char c = getchar(); if (c == '-') { sign = -1; } else { v += c - '0'; } while ((c = getchar()) != EOF && c != ' ' && c != '\n') { v *= 10; v += c - '0'; } return v * sign; }
inline string readstring() { string s; char c; while ((c = getchar()) != EOF && c != '\n' && c != ' ') { s.push_back(c); } return s; }
template <class result_t=std::chrono::milliseconds,class clock_t=std::chrono::steady_clock,class duration_t = std::chrono::milliseconds>
auto since(std::chrono::time_point<clock_t, duration_t> const& start){return std::chrono::duration_cast<result_t>(clock_t::now() - start);}
typedef pair<int, int> pii;
typedef pair<ll, ll> pl;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vpii;
typedef vector<pl> vpl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef vector<vpii> vvpii;
typedef vector<vpl> vvpl;

int press(std::string p);
string alphabet = "ABXY";

string guess_sequence(int n) {
    string p = "";
    if(press("AB")){
        if(press("A")) p = "A";
        else p = "B";
    }else{
        if(press("X")) p = "X";
        else p = "Y";
    }
    if(n == 1) return p;
    string charsUsing = "";
    fo(j, 4){
        if(alphabet[j] == p[0]) continue;
        charsUsing.pb(alphabet[j]);
    }
    for(int i = 1; i < n-1; i++){
        int count = 0;
        string temp;
        fo(j, 4){
            if(alphabet[j] == p[0]) continue;
            if(count == 2) break;
            count++;
            if(count == 1){
                temp = p;
                temp += charsUsing[0];
                continue;
            }
            fo(k, 4){
                if(alphabet[k] == p[0]) continue;
                fo(i2, p.size()) temp+=p[i2];
                temp += charsUsing[1];
                temp += alphabet[k];
            }
        }
        int res = press(temp);
        if(res == i)p+=charsUsing[2];
        else if(res == i+1)p+=charsUsing[0];
        else p+=charsUsing[1];
    }

    if(press(p+"A"+p+"B") == n){
        if(press(p+"A") == n) p += "A";
        else p += "B";
    }else{
        if(press(p+"X") == n) p += "X";
        else p += "Y";
    }

    return p;
}



// namespace {

// constexpr int MAX_N = 2000;
// constexpr int MAX_NUM_MOVES = 8000;

// int N;
// std::string S;

// int num_moves;

// void wrong_answer(const char *MSG) {
//   printf("Wrong Answer: %s\n", MSG);
//   exit(0);
// }

// }  // namespace

// int press(std::string p) {
//   if (++num_moves > MAX_NUM_MOVES) {
//     wrong_answer("too many moves");
//   }
//   int len = p.length();
//   if (len > 4 * N) {
//     wrong_answer("invalid press");
//   }
//   for (int i = 0; i < len; ++i) {
//     if (p[i] != 'A' && p[i] != 'B' && p[i] != 'X' && p[i] != 'Y') {
//       wrong_answer("invalid press");
//     }
//   }
//   int coins = 0;
//   for (int i = 0, j = 0; i < len; ++i) {
//     if (j < N && S[j] == p[i]) {
//       ++j;
//     } else if (S[0] == p[i]) {
//       j = 1;
//     } else {
//       j = 0;
//     }
//     coins = std::max(coins, j);
//   }
//   return coins;
// }

// int main() {
//   char buffer[MAX_N + 1];
//   if (scanf("%s", buffer) != 1) {
//     fprintf(stderr, "Error while reading input\n");
//     exit(1);
//   }
//   S = buffer;
//   N = S.length();

//   num_moves = 0;
//   std::string answer = guess_sequence(N);
//   if (answer != S) {
//     wrong_answer("wrong guess");
//     exit(0);
//   }
//   printf("Accepted: %d\n", num_moves);
//   return 0;
// }

• Subtask 1: 5 / 5
• Subtask 2: 95 / 95