/in/foo.cc: In function 'int main()':
/in/foo.cc:12:33: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'int' [-Wformat=]
   scanf("%d %d",&a[i][0],a[i][1]);
                                 ^
/in/foo.cc:18:15: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   for(i=n-1;i=0;i--)
               ^
/in/foo.cc:10:8: warning: 'n' is used uninitialized in this function [-Wuninitialized]
  for(;i<n;i++)
       ~^~
/in/foo.cc:34:19: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized]
   printf("%d\n",c);
                   ^