Submission #132459

#	Time	Username	Problem	Language	Result	Execution time	Memory
132459		dragonslayerit	Aliens (IOI07_aliens)	C++14	100 / 100	4 ms	376 KiB

aliens

#include <cstdio>
#include <cstring>

long long N;

bool examine(long long x,long long y){
  if(x<1||x>N||y<1||y>N) return false;
  printf("examine %lld %lld\n",x,y);
  fflush(stdout);
  char response[16];
  scanf("%s",response);
  return !strcmp(response,"true");
}

//distance to nearest non-flattened
long long search(long long x,long long y,long long dx,long long dy){
  long long low=0,high=1;
  while(examine(x+high*dx,y+high*dy)){
    high*=2;
  }
  while(high-low>1){
    long long mid=(low+high)/2;
    if(examine(x+mid*dx,y+mid*dy)){
      low=mid;
    }else{
      high=mid;
    }
  }
  return high;
}

int main(){
  long long X,Y;
  scanf("%lld %lld %lld",&N,&X,&Y);
  long long up=search(X,Y,0,1);
  long long down=search(X,Y,0,-1);
  long long M=up+down-1;
  Y+=(up-down)/2;
  long long left=search(X,Y,-1,0);
  long long right=M+1-left;
  X+=(right-left)/2;
  //printf("(%lld,%lld) M=%lld\n",X,Y,M);
  for(long long i=4;i>=0;i--){
    for(long long j=4;j>=0;j--){
      if(examine(X-i*M,Y-j*M)){
	printf("solution %lld %lld\n",X-i*M+2*M,Y-j*M+2*M);
	return 0;
      }
    }
  }
}

Compilation message (stderr)

aliens.cpp: In function 'bool examine(long long int, long long int)':
aliens.cpp:11:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%s",response);
   ~~~~~^~~~~~~~~~~~~~~
aliens.cpp: In function 'int main()':
aliens.cpp:34:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld %lld %lld",&N,&X,&Y);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• 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