Submission #973923

#	Time	Username	Problem	Language	Result	Execution time	Memory
973923		sleepntsheep	Guess the number (BOI20_guess)	C11	100 / 100	1 ms	596 KiB

Guess

#include<stdio.h>

int n;
int main()
{
    scanf("%d",&n);
    int lb=0,ub=n+1;
    while(ub-lb>1)
    {
        int mid=lb+(ub-lb)/2,x;
        printf("? %d\n",mid);fflush(stdout);
        scanf("%d",&x);
        if(x==0)return printf("= %d\n",mid),fflush(stdout),0;
        if(x<0)lb=mid;
        else ub=mid;
    }
}

Compilation message (stderr)

Guess.c: In function 'main':
Guess.c:6:5: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
    6 |     scanf("%d",&n);
      |     ^~~~~~~~~~~~~~
Guess.c:12:9: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |         scanf("%d",&x);
      |         ^~~~~~~~~~~~~~

• Subtask 1: 29 / 29
• Subtask 2: 71 / 71