Submission #896661

#	Time	Username	Problem	Language	Result	Execution time	Memory
896661		Nonoze	Aliens (IOI07_aliens)	C++17	100 / 100	1 ms	708 KiB

aliens

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define int long long
#define sz(x) (int)(x.size())

using namespace std;
using namespace __gnu_pbds;

typedef
tree<
  int,
  null_type,
  less<int>,
  rb_tree_tag,
  tree_order_statistics_node_update>
ordered_set;

int n, k, m;
vector<int> a;
map<pair<int, int>, bool> check;

bool query(int x, int y) {
    if (check.count({x, y})) return check[{x, y}];
    cout << "examine " << x << " " << y << endl;
    string ans; cin >> ans;
    if (ans=="true") return check[{x, y}]=true;
    else return check[{x, y}]=false;
}

void solve() {
    cin >> n;
    int x, y; cin >> x >> y;
    check[{x, y}]=true;
    int tempx=x, tempy=y;
    int ajout=1;
    while (tempx+ajout<=n && query(tempx+ajout, y)) {
        ajout*=2;
    }
    tempx+=ajout/2;
    int l=tempx, r=min(x+ajout, n);
    int rx=l;
    while (l<=r) {
        int mid=l+(r-l)/2;
        if (query(mid, y)) {
            rx=mid;
            l=mid+1;
        } else {
            r=mid-1;
        }
    }


    tempx=x, ajout=1;
    while (tempx-ajout>0 && query(tempx-ajout, y)) {
        ajout*=2;
    }
    tempx-=ajout/2;
    l=max(x-ajout, 1LL), r=tempx;
    int lx=l;
    while (l<=r) {
        int mid=l+(r-l)/2;
        if (query(mid, y)) {
            lx=mid;
            r=mid-1;
        } else {
            l=mid+1;
        }
    }

    m=rx-lx+1;

    ajout=1;
    while (tempy+ajout<=n && query(x, tempy+ajout)) {
        ajout*=2;
    }
    tempy+=ajout/2;
    l=tempy, r=min(y+ajout, n);
    int ry=l;
    while (l<=r) {
        int mid=l+(r-l)/2;
        if (query(x, mid)) {
            ry=mid;
            l=mid+1;
        } else {
            r=mid-1;
        }
    }
    int ly=ry-m+1;
    
    int midx=lx+m/2, midy=ly+m/2;

    while (midx+m<=n && midy+m<=n && query(midx+m, midy+m)) {
        midx+=m, midy+=m;
    }

    while (midx+2*m<=n && query(midx+2*m, midy)) {
        midx+=2*m;
    }

    while (midy+2*m<=n && query(midx, midy+2*m)) {
        midy+=2*m;
    }

    cout << "solution " << midx-2*m << " " << midy-2*m << endl;

    return;
}


signed main() {
    ios::sync_with_stdio(0);
    solve();
    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