/in/foo.cc:9:5: error: stray '\357' in program
    9 |   if（strlen(num)==0){
      |     ^
/in/foo.cc:9:6: error: stray '\274' in program
    9 |   if（strlen(num)==0){
      |      ^
/in/foo.cc:9:7: error: stray '\210' in program
    9 |   if（strlen(num)==0){
      |       ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:9:8: error: expected '(' before 'strlen'
    9 |   if（strlen(num)==0){
      |        ^~~~~~
      |        (
/in/foo.cc:12:16: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   12 |   for(int i=0;i<strlen(num);i++){
      |               ~^~~~~~~~~~~~