Submission #642248

#	Time	Username	Problem	Language	Result	Execution time	Memory
642248		devariaota	Aliens (IOI07_aliens)	C++17	100 / 100	3 ms	288 KiB

aliens

#include <bits/stdc++.h>
#define int long long

using namespace std;

int n, m, x, y;
int d[] = {-4, -3, -2, -1, 1, 2, 3, 4};

bool ask(int x, int y){
    if(x < 1 || x > n || y < 1 || y > n) return false;

    cout << "examine " << x << " " << y << endl;
    string s; cin >> s;
    return (s == "true");
}

int find(int a, int b){
    int tmp = 1;
    while(ask(x + a*tmp, y + b*tmp)) tmp <<= 1LL;
    int l = (tmp>>1LL), r = tmp;
    int ret = l;

    while(l <= r){
        int mid = (l + r)/2LL;
        if(ask(x + a*mid, y + b*mid)){
            l = mid + 1;
            ret = mid;
        } else{
            r = mid - 1;
        }
    }

    return ret;
}

int32_t main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin >> n >> x >> y;
    int L = x - find(-1, 0), R = x + find(1, 0), T = y + find(0, 1), B = y - find(0, -1);
    int mx = (L + R)/2LL, my = (T + B)/2LL;
    int M = (R - L + 1);

    int x = mx, y = my;

    while(ask(x, y)) x -= 2LL*M;
    int left = (x + 2LL*M);
    x = mx, y = my;

    while(ask(x, y)) x += 2LL*M;
    int right = (x - 2LL*M);
    x = mx, y = my;

    while(ask(x, y)) y -= 2LL*M;
    int bottom = (y - 2LL*M);
    x = mx, y = my;

    while(ask(x, y)) y += 2LL*M;
    int top = (y + 2LL*M);

    int ansX = (left + right)/2LL, ansY = (top + bottom)/2LL;

    cout << "solution " << ansX << " " << ansY << endl;
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10