Submission #230161

#	Time	Username	Problem	Language	Result	Execution time	Memory
230161		CaroLinda	Aliens (IOI07_aliens)	C++14	20 / 100	3060 ms	392 KiB

aliens

#include <bits/stdc++.h>

#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")

#define mkt make_tuple
#define debug printf
#define all(x) x.begin(),x.end()
#define lp(i,a,b) for(int i = a ; i< b ; i++)
#define ss second
#define ff first
#define ll long long
#define pb push_back
#define pii pair<int,int>
#define mk make_pair

using namespace std ;

int N , X , Y , M = -1 ;
map< pii , bool > mp ;
string s ;

bool valid(int x, int y) { return 1 <= min(x,y) && max(x,y) <= N ; }

bool test(int x, int y)
{
    if(!valid(x,y) ) return false;

    if( mp.find( mk(x,y) ) != mp.end() ) return mp[ mk(x,y) ] ;

    cout << "examine "<< x << " " << y << endl ;
    cin >> s ;

    mp[ mk(x,y) ] = ( s == "true" ) ;

    return s == "true" ;
}

int main()
{
    ios_base::sync_with_stdio(false) ;
    cin.tie(NULL) ;

    cin >> N >> X >> Y ;

    mp[ mk(X,Y) ] = true ;

    int l = Y , r = N , mid , best_up = l ;
    while(l<=r)
    {
        mid = (l+r)>>1 ;

        if( test(X,mid) ) { best_up = mid ; l = mid + 1; }
        else r = mid - 1 ;

    }

    r = Y , l = 1 , mid ;
    int best_low = r ;

    while(l<=r)
    {
        mid = (l+r)>>1;

        if( test(X,mid) ) { best_low = mid ; r = mid - 1 ; }
        else l = mid + 1 ;

    }

    //I know interval [best_low, best_up] is great
    //But how many squares are there?

    //Testing 3 squares
    if( (best_up-best_low+1) % 5 == 0 )
    {
        M = ( best_up - best_low + 1 )/5 ;

        if( !test( X , best_up - M + 1 ) || test(X,best_up-M) || test( X , best_up - 2*M + 1 ) || !test(X, best_up - 2*M ) || !test(X, best_up - 3*M + 1) || test(X, best_up - 3*M) || test(X, best_up - 4*M + 1) || !test(X, best_up - 4*M) )
            M = -1 ;

    }

    //Testing 2 squares
    if( M == -1 && (best_up - best_low + 1) % 3 == 0 )
    {
        M = ( best_up - best_low + 1 )/3 ;

        if( !test( X , best_up - M + 1 ) || test(X,best_up-M) || test( X , best_up - 2*M + 1 ) || !test(X, best_up - 2*M ) )
            M = -1 ;

    }

    //Testing only one square
    if( M == -1 ) M = best_up - best_low + 1 ;


    //Find the center of any square
    Y = best_up - ( (M-1)/2) ;

    l = X , r = min(N , l + M) ;
    int best_right ;

    while( l <= r )
    {
        mid = (l+r)>>1 ;
        if( test(mid , Y) ) { best_right = mid ; l = mid + 1 ; }
        else r = mid - 1 ;
    }

    l = max(1, X - M ), r = X ;
    int best_left ;

    while( l <= r )
    {
        mid = (l+r)>>1 ;
        if( test(mid, Y) ) { best_left = mid ; r = mid - 1 ; }
        else l = mid + 1 ;
    }

    X = ( best_right + best_left )/2 ;

    while( test(X , Y + 2*M) ) Y += 2*M ;
    while( test(X-2*M , Y) ) X -= 2*M ;

    if( test(X - 2*M , Y + 2*M ) ) X += M , Y -= M ;
    else X += 2*M , Y -= 2*M ;

    cout << "solution " << X << " " << Y << endl ;

}

Compilation message (stderr)

aliens.cpp:4:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
 #pragma GCC optimization ("O3")
 
aliens.cpp:5:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
 #pragma GCC optimization ("unroll-loops")
 
aliens.cpp: In function 'int main()':
aliens.cpp:59:25: warning: right operand of comma operator has no effect [-Wunused-value]
     r = Y , l = 1 , mid ;
                         ^
aliens.cpp:121:22: warning: 'best_left' may be used uninitialized in this function [-Wmaybe-uninitialized]
     X = ( best_right + best_left )/2 ;
         ~~~~~~~~~~~~~^~~~~~~~~~~~~
aliens.cpp:121:22: warning: 'best_right' may be used uninitialized in this function [-Wmaybe-uninitialized]

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