foo.cc:29:20: error: stray '\357' in program
         n=n*10+a[i]；
                    ^
foo.cc:29:21: error: stray '\274' in program
         n=n*10+a[i]；
                     ^
foo.cc:29:22: error: stray '\233' in program
         n=n*10+a[i]；
                      ^
foo.cc: In function 'int main()':
foo.cc:32:5: error: expected ';' before 'for'
     for(x=0;n1;n1/=10)
     ^~~
foo.cc:32:15: warning: statement has no effect [-Wunused-value]
     for(x=0;n1;n1/=10)
               ^
foo.cc:32:22: error: expected ';' before ')' token
     for(x=0;n1;n1/=10)
                      ^

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