/in/foo.cc:10:5: error: stray '\357' in program
   10 |   if（len==0){
      |     ^
/in/foo.cc:10:6: error: stray '\274' in program
   10 |   if（len==0){
      |      ^
/in/foo.cc:10:7: error: stray '\210' in program
   10 |   if（len==0){
      |       ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:10:8: error: expected '(' before 'len'
   10 |   if（len==0){
      |        ^~~
      |        (
/in/foo.cc:13:16: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   13 |   for(int i=0;i<strlen(num);i++){
      |               ~^~~~~~~~~~~~
/in/foo.cc:9:7: warning: unused variable 'len' [-Wunused-variable]
    9 |   int len=strlen(num);
      |       ^~~