oj.uz

Submission #553826

# Submission time Handle Problem Language Result Execution time Memory
553826 2022-04-27T06:59:28 Z Arvin Colors (BOI20_colors) C++11
0 / 100
 1 ms 208 KB 
#include <bits/stdc++.h>

using namespace std;

#define ll long long

set<ll> st;

bool ask(ll n){
	cout << "? " << n << endl;
	
	st.insert(n);
		
	int res;
	cin >> res;
	
	return (res == 1);
}

int main(){
	ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
	
	ll n;
	cin >> n;
	
	ll ans = n;
	ll pos = 2;
	ask(pos);
	
	ll cur = 1;
	ll left = 1, right = n-1;
	while(left <= right){
		ll mid = (left+right) >> 1;
		
		while(st.count(cur)){
			cur++;
		}
		
		bool valid = false;
		if(pos-mid > 0 && !st.count(pos-mid)){
			if(ask(pos-mid)){
				valid = true;
			} else {
				valid = false;
			}
			pos -= mid;
		} else if(pos+mid <= n && !st.count(pos+mid)){
			if(ask(pos+mid)){
				valid = true;
			} else {
				valid = false;
			}
			pos += mid;
		} else {
			ask(cur);
			pos = cur;
			
			if(ask(pos+mid)){
				valid = true;
			} else {
				valid = false;
			}
			pos += mid;
		}
		
		if(valid){
			ans = mid;
			right = mid-1;
		} else {
			left = mid+1;
		}
	}
	
	cout << "= " << ans << endl;
    return 0;
}

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 208 KB OK (6 queries)
2 Incorrect 1 ms 208 KB Hair color 49 was used multiple times
3 Halted 0 ms 0 KB -

Subtask #2
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 208 KB OK (6 queries)
2 Incorrect 1 ms 208 KB Hair color 49 was used multiple times
3 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 208 KB OK (6 queries)
2 Incorrect 1 ms 208 KB Hair color 49 was used multiple times
3 Halted 0 ms 0 KB -

Subtask #4
0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 208 KB OK (6 queries)
2 Incorrect 1 ms 208 KB Hair color 49 was used multiple times
3 Halted 0 ms 0 KB -

Subtask #5
0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 208 KB OK (6 queries)
2 Incorrect 1 ms 208 KB Hair color 49 was used multiple times
3 Halted 0 ms 0 KB -