/in/foo.c:7:14: error: unknown type name 'BigInt'
 int MoveLeft(BigInt a[],int n)
              ^~~~~~
/in/foo.c: In function 'main':
/in/foo.c:23:3: error: unknown type name 'BigInt'
   BigInt Ja[100001];
   ^~~~~~
/in/foo.c:23:3: note: use 'struct' keyword to refer to the type
/in/foo.c:29:21: error: request for member 'str' in something not a structure or union
    scanf("%d",&Ja[i].str);
                     ^
/in/foo.c:30:9: error: request for member 'n' in something not a structure or union
    Ja[i].n=i+1;
         ^
/in/foo.c:36:13: error: request for member 'str' in something not a structure or union
     if(Ja[i].str>=Ja[i+1].str)
             ^
/in/foo.c:36:26: error: request for member 'str' in something not a structure or union
     if(Ja[i].str>=Ja[i+1].str)
                          ^
/in/foo.c:37:13: error: request for member 'str' in something not a structure or union
      Ja[i+1].str=0;
             ^
/in/foo.c:39:11: error: request for member 'str' in something not a structure or union
      Ja[i].str=0;
           ^
/in/foo.c:41:7: warning: implicit declaration of function 'MoveLeft' [-Wimplicit-function-declaration]
   cnt=MoveLeft(Ja,cnt);
       ^~~~~~~~
/in/foo.c:43:22: error: request for member 'n' in something not a structure or union
  printf("%d %d",Ja[0].n,Ja[1].n);
                      ^
/in/foo.c:43:30: error: request for member 'n' in something not a structure or union
  printf("%d %d",Ja[0].n,Ja[1].n);
                              ^