Auto comment: topic has been updated by venkycodes (previous revision, new revision, compare).

The standard answer: Run your code in custom invocation and debug there.

Checker comment: Exit code is 1

......
            if(f) pos=posb+k-x;
            else {cout<<-1; return 1; }
......

you should return 0 but not 1

use return 0 , in line 53 … replace of return 1 ;