Submission #1033030

#	Time	Username	Problem	Language	Result	Execution time	Memory
1033030		goodspeed0208	Colors (BOI20_colors)	C++14	0 / 100	1 ms	344 KiB

Colors

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

signed main() {
	int n;
	cin >> n;
	set<int>st;
	
	int c;
	if (n == 2) {
		cout << "? 1" << endl; cin >> c;
		cout << "? 2" << endl; cin >> c;
		if (c == 0) cout << "= 2" << endl;
		else cout << "= 1" << endl;
		return 0;
	} else if (n == 3) {
		cout << "? 2" << endl; cin >> c;
		cout << "? 3" << endl; cin >> c;
		if (c == 1) cout << "= 1" << endl;
		else {
			cout << "? 1" << endl; cin >> c;
			if (c == 1) cout << "= 2" << endl;
			else cout << "= 3" << endl;
		}
		return 0;
		
	}
	int l = 2, r = n+1, t = 0, ans = n, end = 0;
	//if (n == 3) r = 5;
	cout << "? " << l << "\n"; st.insert(l);
	cin >> c;
	while (!end) {
		if (t) {
			l += 2;
			assert(st.find(l) == st.end());
			cout << "? " << l << endl; st.insert(l);
		} else {
			r -= 2;
			assert(st.find(r) == st.end());
			cout << "? " << r << endl; st.insert(r);
		}
		cin >> c;
		if (c == 0) break;
		else {
			ans = min(ans, r - l);
			if (ans <= 2) break;
		}
		t ^= 1;
	}
	if (c == 1) {
		if (ans == 2) {
			if (t) {
				assert(st.find(r-1) == st.end());
				cout << "? " << r-1 << endl;
			} else {
				assert(st.find(l+1) == st.end());
				cout << "? " << l+1 << endl;
			}
			cin >> c;
			if (c) ans = 1;
		}
		cout << "= " << ans << endl;
		return 0;
	}
	while (c == 0) {
		if (t) {
			r++;
			assert(st.find(r) == st.end());
			cout << "? " << r << endl; st.insert(r);
		} else {
			l--;
			assert(st.find(l) == st.end());
			cout << "? " << l << endl; st.insert(l);
		}
		t ^= 1;
		cin >> c;
		if (c == 1) {
			ans = min(ans, r - l);
			end = 1;
		}
		if (c == 0 && (r - l == ans-1)) {
			end = 1;
		}
	}
	cout << "= " << ans << endl;
}

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