Submission #289228

#	Time	Username	Problem	Language	Result	Execution time	Memory
289228		zecookiez	Aliens (IOI07_aliens)	C++17	50 / 100	3076 ms	512 KiB

aliens

#include <bits/stdc++.h>
using namespace std;
template<class C>constexpr int len(const C&c){return int(c.size());}

const int DDX[13] = {-2, 0, 2, -1, 1, -2, 0, 2, -1, 1, -2, 0, 2};
const int DDY[13] = {-2, -2, -2, -1, -1, 0, 0, 0, 1, 1, 2, 2, 2};
long long N;

bool rng(long long X){
    return 1 <= X && X <= N;
}

map<pair<long long, long long>, bool> memo;
bool query(long long X, long long Y){
    assert(rng(X)); assert(rng(Y));
    if(memo.count(make_pair(X, Y))) return memo[make_pair(X, Y)];
    assert(memo.size() < 300);
    cout << "examine " << X << " " << Y << endl;
    string s; cin >> s;
    return memo[make_pair(X, Y)] = (s == "true");
}

int main(){
    cin.sync_with_stdio(0); cin.tie(0); cout.tie(0);
    long long XS, YS, X1, Y1, X2, SZ, XC, YC; cin >> N >> XS >> YS;
    // find offset from center of current square
    X1 = XS; Y1 = YS;
    while(true){
        for(long long i = 1; X1 + i <= N; i += i){
            if(!query(X1 + i, Y1)){
                X1 += i/2; break;
            }
        }
        if(X1 == N || !query(X1 + 1, Y1)) break;
    }
    X2 = XS;
    while(true){
        for(long long i = 1; X2 - i >= 1; i += i){
            if(!query(X2 - i, Y1)){
                X2 -= i/2; break;
            }
        }
        if(X2 == 1 || !query(X2 - 1, Y1)) break;
    }
    // stupid
    SZ = X1 - X2 + 1; XC = (X1 + X2) / 2;
    while(true){
        for(long long i = 1; Y1 - i >= 1; i += i){
            if(!query(XC, Y1 - i)){
                Y1 -= i/2; break;
            }
        }
        if(Y1 == 1 || !query(XC, Y1 - 1)) break;
    }
    YC = Y1 + SZ / 2;
    for(int i = 0; i < 13; ++i){
        X1 = XC + SZ * DDX[i];
        Y1 = YC + SZ * DDY[i];
        if(!rng(X1) || !rng(Y1)) continue;
        int cnt = 0;
        for(int j = 0; j < 13; ++j){
            XS = X1 + SZ * DDX[j];
            YS = Y1 + SZ * DDY[j];
            if(rng(XS) && rng(YS) && query(XS, YS)) ++cnt;
            else break;
        }
        if(cnt == 13){
            cout << "solution " << X1 << " " << Y1 << endl;
            memo.clear();
            return 0;
        }
    }
    memo.clear();
    assert(false);
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10