Submission #1184022

#	Time	Username	Problem	Language	Result	Execution time	Memory
1184022		kl0989e	Colors (BOI20_colors)	C++17	0 / 100	0 ms	436 KiB

Colors

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

#pragma GCC optimize("Ofast")

#define ll long long
#define fi first
#define se second
#define pb push_back
#define vi vector<int>
#define vl vector<ll>
#define pi pair<int, int>
#define pl pair<ll,ll>
#define all(x) (x).begin(),(x).end()

bool query(ll pos) {
	cout << "! " << pos << endl;
	int ret;
	cin >> ret;
	return ret;
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
	ll n;
	cin >> n;
	ll pos=1;
	ll mul=1;
	ll l=1,r=n-1;
	ll mn=n-1;
	while (l<=r) {
		ll m=l+(r-l)/2;
		pos+=m*mul;
		mul=-mul;
		l=m+1;
		mn=min(mn,pos);
	}
	pos=2-mn;
	mul=1;
	query(pos);
	l=1,r=n-1;
	ll ans=n;
	while (l<=r) {
		ll m=l+(r-l)/2;
		pos+=m*mul;
		mul=-mul;
		if (query(pos)) {
			ans=m;
			r=m-1;
		}
		else {
			l=m+1;
		}
	}
	cout << "= " << ans << endl;
    return 0;
}

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