/in/foo.cc: In function 'int main()':
/in/foo.cc:15:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(i=0;j<M;i++)
  ^~~
/in/foo.cc:50:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
   for(i=0;i<M;i++)
   ^~~
/in/foo.cc:52:26: warning: 'j' may be used uninitialized in this function [-Wmaybe-uninitialized]
    if((start[j]==0&&end[j]==0)||(start[i]==0&&end[i]==0))
                     ~~~~~^