Submission #858732

#	Time	Username	Problem	Language	Result	Execution time	Memory
858732		iskhakkutbilim	Colors (BOI20_colors)	C++17	0 / 100	0 ms	344 KiB

Colors

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

#define int long long
#define ff first
#define ss second
#define all(a) a.begin(), a.end()
int cnt, C, n, x, pref = -1;
void ask(int c){
	cout << "? " << c << endl;
	cnt++;
//	if(pref == -1 or abs(pref - c) >= C) x = 1;
//	else x = 0;
	cin >> x;
}


void answer(int c){
//	cout << "counter " << cnt << endl;
	cout << "= " << c << endl;
	exit(0);
}


main(){
   ios::sync_with_stdio(0);
   cin.tie(0); cout.tie(0);
	cin >> n;
//	cin >> C;
	if(n == 1){
		answer(1);
		return 0;
	}
	ask(1);
	pref = 1;
	int l = 0, r = n + 1;
	while(l + 1 < r){
		int mid = (l + r) >> 1;
		if(pref + mid <= n){
			ask(pref + mid);
			pref = pref + mid;
			if(x) r = mid;
			else l = mid;
		}else if(pref - mid >= 1){
			ask(pref - mid);
			pref = pref - mid;
			if(x) r = mid;
			else l = mid;
		}else{
			if(mid >= n){
				answer(n);
				return 0;
			}
			ask(1);
			pref = 1;
			
			ask(pref + mid);
			pref = pref + mid;
			if(x) r = mid;
			else l = mid;
		}
	}
	answer(r);
	return 0;
}

Compilation message (stderr)

Colors.cpp:25:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   25 | main(){
      | ^~~~

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