Submission #1362170

#	Time	Username	Problem	Language	Result	Execution time	Memory
1362170		uranhishig	Dark Ride (EGOI25_darkride)	C++20	41 / 100	1 ms	508 KiB

Main

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


int ask(string s) {
    int ans;
    cout << "? " << s << endl;
    cin >> ans;
    return ans;
}


void answer(int a, int b) {
    cout << "! " << min(a, b) << " " << max(a, b) << endl;
}

void solve() {
    int n;
    cin >> n;
    if (n <= 30) {
        int ans1 = -1, ans2 = -1;
        for (int i = 0; i < n; i++) {
            string s(n, '1');
            s[i] = '0';
            int x = ask(s);
            if(x == 1 and ans1 == -1) ans1 = i;
            if(x == 1 and ans1 != -1) ans2 = i;
        }
        answer(ans1, ans2);
        return;
    }
    string str(n, '1');
    str[0] = '0';
    if(ask(str) == 1) {
        int l = -1;
        int r = n-1;
        while(l + 1 < r){
            int mid=(l + r)/2;
            string s(n, '0');
            for (int i = 0; i <= mid; i++) s[i] = '1';
            int x= ask(s);
            if(x%2==0) {
                r = mid;
            }
            else{
                l = mid;
            }
        }
        answer(0,r);
        return;
    }


    if (n%2 == 0) {
        if (n % 2 == 0) {
            int l = -1;
            int r = n/2 - 1;
            while (l + 1 < r) {
                int mid = (l + r) / 2;
                string s(n, '0');
                for (int i = 0; i <= mid; i++) {
                    s[i] = '1';
                }
                int x = ask(s);
                if (x %2) {
                    r = mid;
                }
                else {
                    l = mid;
                }
            }
            int ans1 =l;
            l = n/2 - 1;
            r = n - 1;
            while (l+1<r) {
                int mid = (l + r) / 2;
                string s(n, '0');
                for (int i = 0; i <= mid; i++) {
                    s[i] = '1';
                }
                int x = ask(s);
                if (x % 2) {
                    r = mid;
                }
                else {
                    l = mid;
                }
            }
            int ans2=l;
            answer(ans1, ans2);
            return;
        }
    }
}

signed main() {
    solve();
    return 0;
}

• Subtask 1: 0 / 0
• Subtask 2: 9 / 9
• Subtask 3: 15 / 15
• Subtask 4: 17 / 17
• Subtask 5: 0 / 16
• Subtask 6: 0 / 14
• Subtask 7: 0 / 29