题解？

#include<bits/stdc++.h>
#define use using
#define space namespace
#define integer int
#define input cin
#define output cout
#define then ){
#define end }
#define endfunction return 0
#define nexti i++
#define with (
#define it )
#define to >>
#define the <<
#define endline ;
use space std endline
integer main with then
    integer n endline
    input to n endline
    integer a[n]endline
    for with integer i=0;i<n;nexti then input to a[i]endline end
    integer l=0,r=n-1,mid endline
    integer x;input to x endline
    while with l<=r then
        mid= with l+r it /2 endline
        if with a[mid]==x then
            output the mid+1 endline
            endfunction endline
        end 
        if with a[mid]>x then r=mid-1 endline end
        if with a[mid]<x then l=mid+1 endline end
    end output the -1 endline
end