/in/foo.c: In function 'main':
/in/foo.c:13:3: warning: statement with no effect [-Wunused-value]
   for(j; j<k; j++)
   ^~~
/in/foo.c:24:3: warning: statement with no effect [-Wunused-value]
   for(i; i<k;i++)
   ^~~
/in/foo.c:29:3: warning: statement with no effect [-Wunused-value]
   for(j; j>=(n-k); j--)
   ^~~
/in/foo.c:34:3: warning: statement with no effect [-Wunused-value]
   for(i; i>=(n-k); i--)
   ^~~