foo.cc: In function 'int main()':
foo.cc:13:20: error: expected primary-expression before ';' token
  for(int i = 0; i< ; i++) {
                    ^
foo.cc:16:22: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'int' [-Wformat=]
     scanf("%d %d",i,j);
                      ^
foo.cc:16:22: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'int' [-Wformat=]
foo.cc:7:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
foo.cc:9:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&nums[i]);
   ~~~~~^~~~~~~~~~~~~~~
foo.cc:12:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&target);
  ~~~~~^~~~~~~~~~~~~~
foo.cc:16:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d",i,j);
     ~~~~~^~~~~~~~~~~~~

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。