Submission #1038307

#	Time	Username	Problem	Language	Result	Execution time	Memory
1038307		vjudge1	Colors (BOI20_colors)	C++17	0 / 100	1 ms	344 KiB

Colors

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define sort undefined_function // To use stable_sort instead sort 
#define bpc __builtin_popcount
#define ull unsigned long long
#define ld double
#define ll long long
#define mp make_pair
#define F first
#define S second

#pragma GCC optimize("O3")

#ifdef LOCAL 
        #include "debug.h"
#else 
        #define dbg(...) 0
#endif

using namespace __gnu_pbds;
using namespace std;

typedef tree<long long, null_type, less_equal<long long>,
    rb_tree_tag, tree_order_statistics_node_update> Tree;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const ll INF = 9223372036854775807LL;
const ll inf = 2147483647;
const ll MOD = 998244353; //[998244353, 1e9 + 7, 1e9 + 13]
const ld PI = acos(-1);
const ll NROOT = 800;

ll binpow(ll a, ll b, ll _MOD = -1) {
        if (_MOD == -1)
                _MOD = MOD;
        ll res = 1;
        for (; b; b /= 2, a *= a, a %= _MOD)
                if (b & 1) res *= a, res %= _MOD;
        return res;
}

void set_IO(string s) {
#ifndef LOCAL
        string in  = s +  ".in";
        string out = s + ".out";
        freopen(in.c_str(),  "r",  stdin);
        freopen(out.c_str(), "w", stdout);
#endif
}

bool dataOverflow(ll a, ll b) {return (log10(a) + log10(b) >= 18);}
ll gcd(ll a, ll b) {return b ? gcd(b, a % b) : a;}
ll lcm(ll a, ll b) {return a * b / gcd(a, b);}
ll ceil(ll a, ll b) {return (a + b - 1) / b;}
ll invmod(ll a) {return binpow(a, MOD - 2);}

bool query(int x) {
        cout << "? " << x << endl;
        int y;
        cin >> y;

        return (y == 1);
}

int32_t main() {
//        ios_base::sync_with_stdio(0);
//        cin.tie(0);

        int n;
        cin >> n;

        int lst = 1;
        bool ok = query(1);

        int sign = 1;
        for (int i = n - 1; i >= 0; i --) {
                lst += i * sign;
                ok = query(lst);
                sign *= -1;
                if (!ok) {
                        cout << "= " << i + 1 << endl;
                        return 0;
                }
        }

        return 0;
}

Compilation message (stderr)

Colors.cpp: In function 'void set_IO(std::string)':
Colors.cpp:47:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |         freopen(in.c_str(),  "r",  stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
Colors.cpp:48:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |         freopen(out.c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 9
• Subtask 2: 0 / 13
• Subtask 3: 0 / 21
• Subtask 4: 0 / 24
• Subtask 5: 0 / 33