Q18

Consider the following program that attempts to locate an element $x$ in an array $a[ ]$ using binary search. Assume $N > 1$. The program is erroneous. Under what conditions does the program fail? var i,j,k: integer; x: integer; a: array; [1..N] of integer; begin i:= 1; j:= n; repeat k:(i+j) div 2; if a[k] < x then i:= k else j:= k until (a[k] = x) or (i >= j); if (a[k] = x) then writeln ('x is in the array') else writeln ('x is not in the array') end;