Submission #1310543

#	Time	Username	Problem	Language	Result	Execution time	Memory
1310543		StefanSebez	Aliens (IOI07_aliens)	C++20	100 / 100	1 ms	400 KiB

aliens

#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pb push_back
#define ll long long
#define ld long double
#define mp make_pair
ll n,X0,Y0;
bool Ask(ll x,ll y){
    if(x<=0||x>n||y<=0||y>n)return false;
    printf("examine %lld %lld\n",x,y);
    fflush(stdout);
    string s;cin>>s;
    return s=="true";
}
int main(){
    scanf("%lld%lld%lld",&n,&X0,&Y0);
    ll L,R,l,r,d;

    L=Y0,R=Y0;
    l=Y0,r=n;
    while(l<=r){
        ll mid=l+r>>1;
        if(Ask(X0,mid))R=mid,l=mid+1;
        else r=mid-1;
    }
    l=1,r=Y0;
    while(l<=r){
        ll mid=l+r>>1;
        if(Ask(X0,mid))L=mid,r=mid-1;
        else l=mid+1;
    }
    d=R-L+1;
    if(!Ask(X0,L+d/5))d/=5;
    else if(!Ask(X0,L+d/3))d/=3;
    while(Ask(X0,L-2*d))L-=2*d;
    while(Ask(X0,R+2*d))R+=2*d;
    ll Y=L+R>>1;

    L=X0,R=X0;
    l=X0,r=n;
    while(l<=r){
        ll mid=l+r>>1;
        if(Ask(mid,Y0))R=mid,l=mid+1;
        else r=mid-1;
    }
    l=1,r=X0;
    while(l<=r){
        ll mid=l+r>>1;
        if(Ask(mid,Y0))L=mid,r=mid-1;
        else l=mid+1;
    }
    d=R-L+1;
    if(!Ask(L+d/5,Y0))d/=5;
    else if(!Ask(L+d/3,Y0))d/=3;
    while(Ask(L-2*d,Y0))L-=2*d;
    while(Ask(R+2*d,Y0))R+=2*d;
    ll X=L+R>>1;

    printf("solution %lld %lld\n",X,Y);
    fflush(stdout);
    return 0;
}

Compilation message (stderr)

aliens.cpp: In function 'int main()':
aliens.cpp:18:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |     scanf("%lld%lld%lld",&n,&X0,&Y0);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• 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