foo.cc: In function ‘int main()’:
foo.cc:11:26: warning: iteration 9 invokes undefined behavior [-Waggressive-loop-optimizations]
   11 |                 if(b>=a[i]) cnt++;
      |                       ~~~^
foo.cc:9:22: note: within this loop
    9 |         for(int i=1;i<=10;i++)
      |                     ~^~~~