foo.c: In function 'main':
foo.c:5:27: error: expected expression before ')' token
    5 |         for(int a=0;a<n;++){
      |                           ^
foo.c:6:29: error: 'j' undeclared (first use in this function)
    6 |                 for(int j=0;j<a+1;j++){
      |                             ^
foo.c:6:29: note: each undeclared identifier is reported only once for each function it appears in
foo.c:7:36: warning: format '%lld' expects argument of type 'long long int', but argument 2 has type 'int' [-Wformat=]
    7 |                         printf("%lld ",a);
      |                                 ~~~^   ~
      |                                    |   |
      |                                    |   int
      |                                    long long int
      |                                 %d
foo.c:3:21: warning: unused variable 'a' [-Wunused-variable]
    3 |         long long n,a=0;
      |                     ^

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