Submission #642285

#	Time	Username	Problem	Language	Result	Execution time	Memory
642285		mychecksedad	Colors (BOI20_colors)	C++17	0 / 100	0 ms	324 KiB

Colors

/* Author : Mychecksdead */
#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define PI 3.1415926535
#define pb push_back
#define setp() cout << setprecision(15)
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " is " << x << '\n';
const int N = 1e6+100, M = 1e5+10, F = 2147483646, K = 20;


ll n;
bool query(ll p){
    cout << "? " << p << endl;
    bool x; cin >> x;
    return x;
}

void solve(){
    cin >> n;
    if(n == 1){
        cout << "= " << 1 << endl;
        return;
    }

    ll l = 1, r = n - 1, ans = n;




    map<ll, bool> used;

    while(l <= r){
        ll m = (l + r)>>1;
        ll val = m;

        ll a = 64;
        while(used[a] || used[a+m] || a + m > n) a--;
        used[a] = 1;
        used[a+m] = 1;
        ll b = a + m;

        bool x = query(a);
        x = query(b);

        if(x == 1){
            r = m - 1;
            ans = m;
        }else{
            l = m + 1;
        }
    }
    cout << "= " << ans << endl;


}





int main(){
    cin.tie(0); ios::sync_with_stdio(0);
    int T = 1, aa;
    // cin >> T;aa=T;
    while(T--){
        // cout << "Case #" << aa-T << ": ";
        solve();
        cout << '\n';
    }
    return 0;
 
}

Compilation message (stderr)

Colors.cpp: In function 'void solve()':
Colors.cpp:39:12: warning: unused variable 'val' [-Wunused-variable]
   39 |         ll val = m;
      |            ^~~
Colors.cpp: In function 'int main()':
Colors.cpp:68:16: warning: unused variable 'aa' [-Wunused-variable]
   68 |     int T = 1, aa;
      |                ^~

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